Lyon's Den

More review!

2009-05-05T21:09:00.005-06:00

Hey girls, we had some random things to review in class today including signal transduction so hopefully this clears up any confusion in that area.

External signals are converted into responses within the cell

Evolution of Cell Signaling:

Signaling in microbes has much in common with processes in multicellular organisms, suggesting an early origin.

Local and Long–Distance Signaling:

In local signaling, animal cells may communicate by direct contact or by secreting local regulators, such as growth factors or neurotransmitters. For signaling over long distances, both animals and plants use hormones; animals also signal along nerve cells.

The Three Stages of Cell Signaling:

Earl Sutherland discovered how the hormone epinephrine acts on cells. The signal molecule epinephrine binds to receptors on a cell′s surface (reception), leading to a series of changes in the receptor and other molecules inside the cell (transduction) and finally to the activation of an enzyme that breaks down glycogen (response).

Reception: A signal molecule binds to a receptor protein, causing it to change shape

The binding between signal molecule (ligand) and receptor is highly specific. A conformational change in a receptor is often the initial transduction of the signal

Intracellular Receptors:

Intracellular receptors are cytoplasmic or nuclear proteins. Signal molecules that are small or hydrophobic and can readily cross the plasma membrane use these receptors.

Receptors in the Plasma Membrane:

A G–protein–linked receptor is a membrane receptor that works with the help of a cytoplasmic G protein. Ligand binding activates the receptor, which then activates a specific G protein, which activates yet another protein, thus propagating the signal along a signal transduction pathway.

Receptor tyrosine kinases react to the binding of signal molecules by forming dimers and then adding phosphate groups to tyrosines on the cytoplasmic side of the other subunit of the receptor. Relay proteins in the cell can then be activated by binding to different phosphorylated tyrosines, allowing this receptor to trigger several pathways at once.

Specific signal molecules cause ligand–gated ion channels in a membrane to open or close, regulating the flow of specific ions.

Transduction: Cascades of molecular interactions relay signals from receptors to target molecules in the cell

Signal Transduction Pathways:

At each step in a pathway, the signal is transduced into a different form, commonly a conformational change in a protein.

Protein Phosphorylation and Dephosphorylation:

Many signal transduction pathways include phosphorylation cascades, in which a series of protein kinases each add a phosphate group to the next one in line, activating it. Phosphatase enzymes soon remove the phosphates.

Small Molecules and Ions as Second Messengers:

Second messengers, such as cyclic AMP (cAMP) and Ca2+, diffuse readily through the cytosol and thus help broadcast signals quickly. Many G proteins activate adenylyl cyclase, which makes cAMP from ATP. Cells use Ca2+ as a second messenger in both G–protein and tyrosine kinase pathways. The tyrosine kinase pathways can also involve two other second messengers, DAG and IP3. IP3 can trigger a subsequent increase in Ca2+ levels.

Response: Cell signaling leads to regulation of cytoplasmic activities or transcription

Cytoplasmic and Nuclear Responses:

In the cytoplasm, signaling pathways regulate, for example, enzyme activity and cytoskeleton rearrangement. Other pathways regulate genes by activating transcription factors, proteins that turn specific genes on or off.

Fine–Tuning of the Response:

Each catalytic protein in a signaling pathway amplifies the signal by activating multiple copies of the next component of the pathway; for long pathways, the total amplification may be a millionfold or more. The particular combination of proteins in a cell gives the cell great specificity in both the signals it detects and the responses it carries out. Scaffolding proteins can increase signal transduction efficiency. Pathway branching and cross–talk further help the cell coordinate incoming signals. Signal response is terminated quickly by the reversal of ligand binding.

Quizlet:

1. Amplification of a chemical signal occurs when
a. a receptor in the plasma membrane activates several G– protein molecules while a signal molecule is bound to it.
b. a cAMP molecule activates one protein kinase molecule before being converted to AMP.
c. phosphorylase and phosphatase activities are balanced.
d. receptor tyrosine kinases dimerize upon ligand binding.
e. both a and d occur.

2. Which of the following provides the best evidence that cell–signaling pathways evolved early in the history of life?
a. They are seen in “primitive” cells such as yeast.
b. Yeast cells signal each other for mating.
c. Signal transduction molecules found in distantly related organisms are similar.
d. Signals can be sent long distances by cells.
e. Most signals are received by cell surface receptors.

3. Consider this pathway: epinephrine → G–protein–linked receptor → G protein → adenylyl cyclase → cAMP. Identify the second messenger.
a. cAMP
b. G protein
c. GTP
d. adenylyl cyclase
e. G–protein–linked receptor

4. Which observation suggested to Sutherland the involvement of a second messenger in epinephrine′s effect on liver cells?
a. Enzymatic activity was proportional to the amount of calcium added to a cell–free extract.
b. Receptor studies indicated that epinephrine was a ligand.
c. Glycogen breakdown was observed only when epinephrine was administered to intact cells.
d. Glycogen breakdown was observed when epinephrine and glycogen phosphorylase were combined.
e. Epinephrine was known to have different effects on different types of cells.

5. Binding of a signal molecule to which type of receptor leads directly to a change in the distribution of anions and/or cations on opposite sides of the membrane?
a. receptor tyrosine kinase
b. G–protein–linked receptor
c. phosphorylated receptor tyrosine kinase dimer
d. ligand–gated ion channel
e. intracellular receptor

6. Protein phosphorylation is commonly involved with all of the following except
a. regulation of transcription by extracellular signal molecules.
b. enzyme activation.
c. activation of G–protein–linked receptors.
d. activation of receptor tyrosine kinases.
e. activation of protein kinase molecules.

7. Signal transduction pathways benefit cells for all of the following reasons except
a. they help cells respond to signal molecules that are too large or too polar to cross the plasma membrane.
b. they enable different cells to respond appropriately to the same signal.
c. they help cells use up phosphate generated by ATP breakdown.
d. they can amplify a signal.
e. variations in the signal transduction pathways can enhance response specificity.

8. Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because
a. they are species specific.
b. they always lead to the same cellular response.
c. they amplify the original signal manyfold.
d. they counter the harmful effects of phosphatases.
e. the number of molecules used is small and fixed.

9. The activation of receptor tyrosine kinases is always characterized by
a. dimerization and phosphorylation.
b. IP3 binding.
c. a phosphorylation cascade.
d. GTP hydrolysis.
e. channel protein conformational change.

10. Lipid–soluble signal molecules, such as testosterone, cross the membranes of all cells but affect only target cells because
a. only target cells retain the appropriate DNA segments.
b. intracellular receptors are present only in target cells.
c. most cells lack the Y chromosome required.
d. only target cells possess the cytosolic enzymes that transduce the testosterone.
e. only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Answers:
1. A
2. C
3. A
4. C
5. D
6. C
7. C
8. C
9. A
10. B

Review: Protein Synthesis!

2009-05-02T18:17:00.021-06:00

I thought that a review on protein synthesis, including transcription, RNA processing and translation would be helpful. On Friday B block didn't really have class, and in C block we just watched a movie. The chapter 50 packet is now due on Monday, and keep reviewing!

PROTEIN SYNTHESIS
Protein synthesis is the process that describes how enzymes and other proteins are made from DNA.

The three steps in protein synthesis are transcription, RNA processing, and translation.

Transcription:
This is the process by which DNA makes RNA. The three types of RNA are mRNA, tRNA, and rRNA. Messenger RNA (mRNA) carries messages directly from DNA to the cytoplasm and varies in length, depending on the length of the message. Transfer RNA (tRNA) is shaped like a cloverleaf and carries amino acids to the mRNA at the ribosome. Ribosomal RNA (rRNA) is strcutural, this makes up the ribosome, which is formed in the nucleolus.

Transcription consists of three stages: initiaition, elongation, and termination.

At the start of initiation an enzyme, RNA polymerase, recognizes and binds to DNA at the promoter region. This begins to unzip the DNA into two strands. A promoter region for mRNA transcriptions often contains the sequence T-A-T-A (the TATA box). The completed assembly of transcription factors and RNA polymerase bound to the promoter is called the transcription initiation complex. Once RNA polmerase is attached to promoter, DNA transcription of the DNA template begins.

Elongation occurs as the RNA polymerase unzips the DNA and assembles RNA nucleotides using one strand of the DNA as a template. As in DNA replication , elongation of the RNA molecule occurs in the 5' --> 3' direction. In contrast to DNA replication, new nucleotides (rather than DNA nucleotides), and only on DNA strand in transcribed.
Termination is the final stage. It continues for a short distance after the RNA polymerase transcribes the termination sequence. At this point, mRNA is cut free from the DNA template. In eukaryotes, the termination region often ocntains the DNA sequence AAAAAAA.
RNA Processing
Before the newly formed RNA strand is shipped out to the ribosome in the cytoplasm, it is altered or processed by a series of enzymse.

A 5' cap consisting of a modified guanine nucleotide is added to the 5' end. This cap helps protect the RNA strand from degradation by hydrolytic enzymes and also helps the RNA strands bind to the ribosome in the cytolpasm.

A poly-A tail is attahced to the 3' end of the mRNA. The tail consists of 30 to 200 adenine nucleotides. The tail protects the RNA strand from degradation by hydrolytic enzymes, helps the ribosome attach to the RNA, and facilitates the release of the RNA into the cytplasm.

Noncoding regions of the mRNA called introns or intervening sequences are removed by the snRNPs, small nuclear ribonucleoproteins, and splicesomes.This removal allows only exons, which are expressed sequences, to leaves the nucleus. As a result of this processing, the mRNA that leaves the nucleus is a great deal shorter than the original transcription unit.

Translation
After transcription, the mRNA, tRNA, and ribosomal subunits are transported across the nuclear envelope and into the cytoplasm. In the cytoplasm, amino acids attach to the 3' end of the tRNA's, forming an aminoacyl-tRNA. The reaction requires an enzyme specific to each tRNA and the energy from one ATP. The amino acid-tRNA bond that results is a high-energy bond, creating a activated amino acid.

Like transcription, translation is categorized into three steps: intiation. elongation, and termination. Energy for translation is provided by several GTP molecules. GTP acts as an energ supplier in the same manner as ATP.

Intiation begins with when mRNA becomes attached to a subunit of the ribosome. The first codon is always AUG. It codes for methione and must be positioned correctly in order for transcription of an amino acid sequence to begin. At this point, the ribosomal subunit is a complex of mRNA, AUG, the tRNA anticodon, UAC, the amino acid methione.

Elongation continues as tRNA brings amino acids to the ribosome and a polypeptide chain is formed.

Termination of an mRNA strand is complete when a ribosome reaches one of three termination or stop codons. A release factor hydrolyzes the bond between ther tRNA and the last amino acid of the polypeptide chain. The polypeptide is freed from the ribosome, and the mRNA is broken down.

Quiz:

1) If AUU is the codon, what is the anticodon?
a. AUU
b. TAA
c. UUA
d. UAA

2) What are the regions of DNA called that code for proteins?
a. introns
b. codons
c. anticodons
d. exons

3) The end products of translation are
a. polypeptides
b. amino acids
c. RNA
d. DNA

4) Which if the following contains a code for a protein?
a. mRNA
b. RNA polymerase
c. rRNA
d. tRNA

5) Proteins synthesis consists of all the following steps except:
a. translation
b. transcription
c. replication
d. elongation

ANSWERS: 1)D 2)D 3)A 4)A 5)C

Just keep reviewing the rest of the week!!!! :-)

2009-04-28T19:26:00.008-06:00

Chapter 43- The Body's Defenses

In innate immunity, recognition and response rely on shared pathogen traits

Innate immune responses include barrier defenses as well as defenses to combat pathogens that end the body

1. Barrier defenses skin and the mucous membranes cover the surface and line the openings of the animal body, and they provide an external barrier against infecting agents

First Line of Defense
Specifically, skin, antimicrobial proteins are in the saliva, cilia lines the lungs to sweep invaders out, gastric juice of the stomach kills most microbes, and symbiotic bacteria in the digestive tract also serve as first line of denfense

Microbes that get through the skin-- for instance, in a cut-- encounter certain types of white blood cells called neutrophils that ingest and destroy them in a process called phagocytosis

Here is a link to a video showing neutrophil phagocytosis

http://esgweb1.nts.jhu.edu/cellbio/devreotes/neutrophil.mov

2. Cellular innate defenses combat pathogens that get through the skin-- for example, in a cut. They include phagocytic white blood cells and antimicrobial proteins.

Phagocytic White Blood Cells

Neutrophils are white blood cells that ingest and destroy microbes in a process called phagocytosis
Monocytes are another type of phagocytic leukocyte. They migrate into tissues and develop into macrophages, which are giant phagocytic cells
Eosinophils are leukocytes that defend against parasitic invaders such as worms by positioning themsleves near the parasite's wall and discharging hydrolytic enzymes

Antimicrobial Proteins

Inteferon proteins provide innate defense against viral infections. They cause cells adjacent to injected cells to produce substances to inhibit viral replication

The complement system consists of roughly 30 proteins with a variety of functions. One function is to lyse invading cells.

The major histocompatibility complex, or MHC, is the mechanism by which the immune system is able to differentiate between self and nonself cells. The MHC is a collection of glycoproteins that exists on the membranes of all body cells.

3. The inflammatory response occurs where physical injury occurs to a tissue, and occurs in response to chemical signals (Second line of defense). For example, histamines are released by basophils and most cells (two ypes of leukocytes) in response to injury. Histamines trigger the dilation and permeability of nearby capillaries. This aids in delivering clotting agents (white blood cells) to the injured area. Vasodilation causes redness, and increase in temperature, and and swelling. Histamines cause watery, itchy eyes, and sneezing. We fight histamine reactions with antihistamines.

The third line of defense is the immune response and it differs from the inflammatory response in that it targets specific antigens.

4. Natural Killer (NK) cells help recognize and remove diseased cells

In acquired immunity, lymphocyte receptors provide pathogen- specific recognition

Vertebrates have two types of: B lymphocytes (B cells) which proliferate in the bone marrow, and T lymphocytes (T cells) where lymphocytes mature in the thymus. They circulate through the blood and lymph, and both recognize particular microbes and are said to show specificity.

Antigens are foreign molecules that elicit a response by lymphocytes

Antibodies are proteins secreted by B cells in an immune response. Each anitibody is specific to a particular antigen. There are five classes of anitbodies (or immunoglobins): IgA, IgD, IgE, IgG, IgM.

Antigen receptors are located on the antigen and allow B and T cells to recognize them as antigen receptors on T cells are called T cell receptors, which combat the antigen, and the other consists of memory cells, which are long-lived and bear receptors for the same antigen.

Plasma cells are B cells that release their specific antibodies which then circulate through the body, binding to antigens.

Memory cells are lon-lived B cells that do not release their antibodies in response to the immediate antigen invasion. Instead, the memory cells circulate in the body and respond quickly to eliminate any subsequent invasion by the same antigen. This mechanism provides immunity to many diseases after the first occurence of the disease.

Here is a link to a video about white blood cells, T-cells, NK cells, and cancer cells

http://www.metacafe.com/watch/yt-aSpRpf1Ny9A/immune_system_white_blood_cells_t_cells_cancer_cells/

Multiple Choice Questions

1. Which if these cells produce and secrete antibodies?

a) macrophages
b) cytotoxic T cells
c) helper T cells
d) bacterial cells
e) plasma cells

2. What kind of white blood cells defend against parasitic invaders?
a) basophils
b) monocytes
c) eosinophils
d) neutrophils
e) histamines

3. ________ proliferate in the bone marrow and ________ mature in the thymus.

a) B cells, T cells
b) NK cells, T cells
c) T cells, B cells
d) B cells, NK cells
e) NK cells, B cells

4. Histamine is secreted by ________.

a) eosinophils
b) monocytes
c) basophils
d) T lymphocytes
e) B lymphocytes

Answers: 1. e, 2. c, 3. a, 4. c

Notes reposted from March 30th, due to technical difficulties with my blog account.

Review: Cellular Respiration

2009-04-27T18:13:00.011-06:00

Today in class we did interactive slides on the smart board to start our review for the AP test.

Here are the topics the slides covered:

-sources and sinks

-hydrogen bonds

-the four properties of water:

+cohesion and adhesion (transpiration)

+the fact that water is less dense as a solid than as a liquid

+surface tension

+high speific heat

-modes of selection

+stabilizing

+directoinal

+disruptive

-speciation (*a lot of people seemed to need to review this one)

-macromolecules

-apoplastic and symplastic routes

-recombinant DNA and vectors
-guttation, xenophytes, C3 C4 and CAM plants
-stages of mitosis

-animal junctions

+desmosome

+tight junction

+gap junction

-plant junctions

+plasmodesmata

-monomers, polymers, and bonds

-bacteriophages

-the structure of a protein

I, personally, feel that I need to brush up on CELLULAR RESPIRATION. Here is a quick review. Hopefully it helps everyone out!

Cellular respiration is the breakdown of sugars that occurs in teh presence of oxygen. Carbohydrates, fats, and proteins can all be broken down to release energy in cellular repsiration. However, glucose is the primary nutrient fuel molecule that is used in cellular respiration to release energy.

Below is the standard equation for cellular respiration:

C6H12O6 + O2 → CO2 + H2O + Energy (as ATP)

Cellular respiration is aerobic respiration (oxygen is present).

Glycolysis is the first process in cellular respiration:

Glycolysis is the decomposition of glucose to two pyruvate molecules. The 6-carbon glucose molecule is split into two 3-carbon sugars through a long series of steps.

There is an ATP consuming phase and an ATP producing phase.

First, 2 ATP are consumed. In the next phase, 4 ATP are produced as well as 2 NADH. The net gain of ATP is 2.

*NADG is a conenzyme that forms when NAD+ combines with two energy-rich electrons and H+.

The Krebs Cycle is the second process:

It occurs in the mitochondrial matrix. In it, glucose is completely broken down and the final product is CO2.

The cycle has 8 steps, and each is catalyzed by a different enzyme:

1. Acetyl CoA adds iots two-carbon acetyl group to oxoaloacetate, producing citrate.

2. Citrate is converted to its isomer, isocitrate, by removal of one water molecule and addition of another.

3. Isocitrate is oxidized, reducing NAD+ to NADH. Then the resultinf compound loses a CO2 molecule.

4. Another CO2 is lostm and the resulting compound is oxidized, reducing NAD+ to NADH. THe remaining molecule is then attached to coenzyme A by an unstable bond.

5. CoA is displaced by a phosphate group, which is transferred to GDP, forming GTP, a molecule with functions similar to ATP.

6. Two hydrogens are transferred to FAD, forming FADH2 and oxidizing succinate.

7. Addition of a water molecule rearranges bonds in the substrate.

8. The substrate is oxidized, reducing NAD+ to NADH and regenerating oxaloacetate.

Each cycling requires the input of a 2-carbon acetyl co-a molecule, and two carbons are released in the course of the cyle as CO2.

For every 1 turn of the cycle, the net results are:

2 CO2

1 ATP

3 NADH

1 FADH2

For every 2 turns of the cylce, the net results are:
4 CO2

2 ATP

6 NADH

2 FADH2
**Both glycolysis and the Krebs Cycle are substrate level phosphorylation. This means that a phosphate group and its associated energy is transferred to ADP to from ATP. The substrate molecule (the one with the phosphate group) donates the high energy phosphate group.

Oxidative phosphorylation is the last process of the cellular respiration:

Oxidative phosphorylation is the process of extracting ATP from NADH and FADH2. Electrons from NADH and FADH2 pass along an electron transport chain.

The electron transport chain consists of molecules (mainly proteins) embedded in teh inner mitochondrial membrane. Sitting on top of these proteins embedded in the membrane are associated molecules that are alternately reduced and oxidized as the accept and donate electrons.

* In oxidation, electrons are loast. In reduction, they are added.

The first electron acceptor in the ETC is a flavoprotein called flavin mononucleotide (FMN) and it accepts and electron from NADH.

The electron is passd down a series of molecules to oxygen, the final electron acceptor. Then, it is combined with hydrogen atoms to form water.

*FADH2 and NADH both donate electrons in the chain

The ETC does not make any ATP itself. Its reactions are coupled to others to make ATP in chemiosmosis.

In chemiosmosis, a hydrogen pump pumps H+ ions against their concentration gradient across the mitochondrial membrane. This creates a proton gradient. Protein complexes called ATP synthases embedded in the membrane use the energy from the proton gradient. The H+ ions flow back into the mitochondrial matrix through the ATP synthase. The flow drives the oxidative phosphorylation of ADP to ATP. Oxidative phosphorylation results in about 34 ATP molecules.

This makes the total number of ATP produced by cellular respiration about 38.

To sum it up, here are the products of each step of cellular respiration:

GLYCOLYSIS: 2 net ATP, 2 NADH

ACETYL CoA-PYRUVATE: 2 NADH, 2 CO2

KREB'S CYCLE: 2 net ATP, 6 NADH, 2 FADH2, 4 CO2

OXIDATIVE PHOSPHORYLATION: 34 net ATP

* Here is a really good video that Mrs. Lyon showed us in class when we first learned cellular respiration: http://www.youtube.com/watch?v=Biq1xo-1eyo&feature=related.

Questions:

1. Which of the following sequences correctly indicates the potential ATP yield of the indicated molecules from greatest ATP yield to least ATP yield?

a) Pyruvate, ethanol, glucose, acetyl CoA

b) Glucose, pyruvate, acetyl CoA, NADH

c) Glucose, pyruvate, NADH, acetyl CoA

d) Glucose, FADH2, acetyl CoA, pyruvate

e) Glucose, FADH2, NADH, pyruvate

2. Cells do not catabolize carbon dioxide because

a) its double bonds are too stable to be broken

b) CO2 has fewer bonding electrons than other organic compounds

c) CO2 is already completely reduced

d) CO2 is already completely oxidized

e) the molecule has too few atoms

3. In mitochondria, exergonic redox reactions

a) are the source of energy driving projaryotic ATP synthesis

b) are directly coupled ot substrate-level phosphorylation

c) provide the energy that establishes the proton gradient

d) reduce carbon atoms to carbon dioxide

e) are coupled via phosphorylated intermediates to endergonic processes

4. When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

a) the pH of the matrix increases

b) ATP synthase pumps protons by active transport

c) the electrons gain free energy

d) the cytochromes phosphorylate ADP to form ATP

e) NAD+ is oxidized

5. The final electron acceptor of the ETC that functions in aerobic oxidative phosphorylation is

a) oxygen

b) water

c) NAD+

d) pyruvate

e) ADP

Answers:

1- B

2- D

3- C

4- A

5- A

This Week:

Review, review, and more review.

Remember: Chapter 50 take home is due Friday.

Only 2 more weeks until the exam! Keep up the hard work!

The End (of Chapter 50)

2009-04-26T18:40:00.007-06:00

Alright girls, here are the final notes!

Chemoreception – Taste and Smell
Taste buds are modified epithelial cells situated on different parts of the tongue and mouth

Movement and Locomotion
Locomotion is the movement from place to place.
Hydrostatic skeletons consist of fluid held under pressure in a closed body compartment
Exoskeletons are hard encasements on the surface of an animal, such as is found in the grasshopper. Endoskeletons consist of hard supporting elements buried within the soft tissues of an animals. Ex: the human body skeleton

Skeletal muscles are attached to bones and responsible for the movement of bones they consist of long fibers, each of which is a single muscle cell. A muscle fiber is a bundle of myofibrils which are composed of myofilaments called actin (thin filaments) and myosin (thick filaments).

The sarcomere is the basic contractile unit of the muscle. Z lines make up the border of the sarcomere. The I band is the area near the end of the sarcomere where only thin filaments exists. The A band is the entire length of the thick filaments.

Muscle contraction occurs when the length of the sarcomere is reduced.
There are two different types of muscle fibers: fast-twitch muscle fibers, which are used for fast, powerful contractions and slow-twitch muscle fibers, which are used for slow, long-lasting contractions
The sliding filament model states that the thick and thin filaments slide past each other so that their degree of overlap increases. This is dependent on the interaction between the actin and myosin molecules that make up the thin and thick filaments

Muscle cells contract when stimulated by a motor neuron.
In the first stage of muscle contraction, muscle contraction is stimulated by an action potential in a motor neuron that makes as synaptic connection with the muscle cell releases acetylcholine at the neuromuscular junction. This depolarizes the muscle cell and triggers the action potential.
In the second stage of muscle contraction, the action potential spreads along T tubules (transverse tubules); changes the permeability of the sarcoplasmic reticulum to calcium ions, and the newly released calcium ions bind to troponin and cause it to move, exposing the myosin sites on the actin; the muscle contracts.

The End

Review Questions:
1. All of the following are involved in the contraction of muscle cells EXCEPT:
a) actin
b) cAMP
c) mysoin
d) tropomyosin
e) troponin

2. Muscle cells are stimulated by neurotransmitters released from the tips of
A) T tubules
B) motor cell axons
C) motor cell dendrites
D) sensory cell dendrites
E) sensory cell axons

3. Which of the following does not form part of the thin filaments of a muscle cell?
a) tropomyosin
b) calcium-binding site
c) troponin
d) myosin
e) actin

Answers:
1. b
2. b
3. d

Don't forget that the chapter 49 and 50 take home quiz is due on Friday!

We only have two weeks left until the AP Exam so it's time to start reviewing. . . Remember, about 25% of the exam will be on Molecular and Cellular Biology (Chemistry of Life, Cells, Cellular Energy), about 25% will be on Genetics and Evolution (Heredity, Molecular Genetics, Evolutionary Biology) and about 50% will be on Organisms and Populations (Structure and Function of Plants and Animals, Ecology, Taxonomy of Organisms).

CHAPTER 50: Sensory and Motor Mechanisms

2009-04-24T12:18:00.003-06:00

Hello AP Bio, These are yesterdays (Thursdays) notes. It's not a lot we kinda ran through them pretty fast. Mrs. Lyon will go more into depth today.
Mechanoreceptors are receptors stimulated by physical stimuli, such as pressure, touch, stretch, motion, or sound
Thermoreceptors respond to either heat or cold and help maintain body temperature by keeping the core temperature stable.

Chemoreceptors transmit information about solute concentration in a solution. Gustatory (taste) receptors and olfactory (smell) receptors are two types of chemoreceptors.

Photoreceptors and Vision
Compound Eyes (in insects and crustaceans) consist of up to several thousand light detectors called ommatidia, each of which has its own lens.

Single-lens eyes are found in vertebrates and some invertebrates.

The eyeball in single-lens eyes is made up of two outer layers, the sclera (which in the front of the eye is the cornea-responsible for acting as a lens) and the choroid. The eyeball also contains the pupil, which is the hole in the center of the iris, and the retina, which contains the photoreceptor cells.

The sclera is an extension of the cornea.
Aqueous humor fills the anterior cavity of the eye, and the vitreous humor fills the posterior cavity of the eye.

The retina contains rod cells and cone cells, two types of photoreceptors.

Rhodopsin is the light-absorbing pigment that triggers a signal transduction pathway that ultimately leads to sight.

Identify the part of a single-lens eye with this link:
http://courses.washington.edu/chordate/453photos/skull_photos/human_ear_ossicles.jpg

Hearing and Equilibrium

There are three regions in the mammalian ear.

1. The outer ear, which is the external pinna and auditory canal. These collect sounds and bring them to the tympanic membrane (eardrum), which separates the outer ear from the middle ear.

2. The middle ear, in which vibrations are conducted through three small bones collectively called ossicles (individually, the malleus, incus, and stapes) and through the oval window.

3. Then the vibrations are conducted to the inner ear, which consists of a labyrinth of channels lined by membrane and containing fluid, all situated in bone.

The inner ear contains the cochlea, a two-chambered organ, which is involved in hearing.

The organ of Corti, which is in the cochlea, contains the receptors of the ear, which are hair cells with hairs that project into the cochlear duct.

The cochlea transduces the energy of the vibrating fluid into action potentials, in a wave that dissipates at the round window.

Some organs in the inner ear are responsible for detecting body position and balance. These are the semicircular canals.

~Quick Quiz~
1. The Ossicles in the ear contain three bones. What are they called?
a. the malleus, incus, and staple
b. the incas, mallus, and stapes
c. the malleus, incus, and stapes
d. the stepes, incas, and mallous

2. What part of the ear gives us balance?
a. semicircular canal
b. the pinna
c. the malleus
d. the incus

3. Which part of the eye reacts to color?
a. cornea
b. rod cell
c. rhodopsin
d. cone cell

answers: c,a,d

Sensory and Motor Mechanisms

2009-04-22T22:06:00.007-06:00

Hello children of AP Biology-

Today both blocks went over the most recent packet (chapters 46 through 48 I believe). Then, B, I think you guys started chapter 50. Ms. Lyon decided she was done teaching C block shortly after the packet, so we did nothing else. I'm assuming chapter 50 is one of our last... ah the beginning of the end. I'm just going to give everyone a quick overview of it. Also, chapter 50 vocabulary quiz is tomorrow as I'm sure you knew. Meghan kindly posted all the words yesterday, so I'll just pick several for a short quiz at the end. STUDY UP!

Chapter 50: Sensory and Motor Mechanisms

section 50.1

-basically, your body has two parts to its nervous system: the PNS and CNS

-the PNS is the peripheral nervous system (everything but the brain and spinal column): sensory reception occurs in this system

-a sensory receptor (made of specialized neurons or epithelial cells) detect stimuli--either internal or ext

ernal

-the receptor converts the stimulus energy to a change in t

he membrane potential of that receptor (look back at the action potential graph)

-this stimulus signal is passed along through action po

tentials to the CNS: the central nervous system (consisting of your spinal column and brain)

-the brain now goes through a process called PERCEPTION: it understands what is happening (the sound, smell, etc.)

-the signal is amplified and then the receptor cell either produces action potentials or releases a neurotransmitter

-there are numerous types of chemoreceptors (detect solute concentrations), mechanoreceptors (pressure, touch, stretch, motion, sound), electromagnetic receptors (electromagnetic radiation), thermoreceptors (temperature), and pain receptors

Alright guys, there's a baby intro to chapter 50. Here is a quiz over a few of the words for the vocab quiz tomorrow.

1. The broad region that corresponds to the length of the thick filaments of microfibrils is __________.

a) Z Line

b) A Band

c) I Band

2. The photoreceptor in the vertebrate eye that detects color during the day is _________.

a) Cone Cell

b) Trypomyosin

c) Rod Cell

3. A type of mechanoreceptor that detects sound waves and other forms of movement in air and water is _________.

a) Rhodopsin

b) Thin Filament

c) Hair Cell

Answers: (1) B (2) A (3) C

Good luck on the quiz!

shirts

2009-04-22T06:18:00.002-06:00

Hey sorry I forgot to post this last night... but here are the potential bio shirts morgan and I designed. If you have any suggestions for changes, just post them as a response to this, and I'll get on it asap. I think all of C block is getting them. If anyone from B block wants one let me know.

-Linds

CLICK HERE to take a gander.

Nervous System

2009-04-21T19:50:00.008-06:00

Hi ladies! Sorry for posting this so late. Don't forget that ch 50 is due tomorrow, the ch 46-48 take home is due tomorrow, and we have a ch 48/49 vocab quiz. IT'S ALSO LATE START! :)

Today in C block Lindsey showed us the awesome design for the AP Bio t-shirt. They are really cute and everyone should get one! She's going to post the link on the blog so that B block can see the shirts, too. We also took a vocab quiz and took more notes on the nervous system.

Chapter 50 Vocab:
Cardiac muscle
a type of muscle that forms the contractile wall of the heart. Its cells are joined by intercalated disks that relay each heartbeat

sarcoplasmic reticulum
a specialized endoplasmic reticulum that regulates the calcium concentration in the cytosol

Z lines
The borders of a sacromere

tropomyosin
the regulatory protein that blocks the myosin-binding sites on the actin molecules

A band
the broad region that corresponds to the length of the thick filaments of myofibrils

I band
The area near the edge of the sacromere where there are only thin filaments

sarcomere
the fundamental, repeating unit of striated muscle, deliminated
By the Z lines

Cone cell
one of two types of photoreceptors in the vertebrate eye; detects color during the day

thick filament
a filament composed of staggered arrays of myosin molecules; a component of myofibrils in muscle fibers

Hydrostatic skeleton
a skeletal system composed of fluid held under pressure in a closed body compartment; the main skeleton of most cnidarians, flatworms, nematods, and annelids

rod cell
one of two kinds of photoreceptors in the vertebrate retina; sensitive to black and white and enables night vision

thin filament
the smaller of the two myofilaments consisting of two strands of actin and two strands of regulatory protein coiled around one another

Myofilaments

the thick and thin filaments that form the myofibrils

Hair cell
a type of mechanoreceptor that detects sound waves and other forms of movement in air or water

rhodopsin
a visual pigment consisting of retinal and opsin. When rhodopsin absorbs light, the retinal changes shape and dissociates from the opsin, after which it is converted back to its original form

Amplification
the strengthening of stimulus energy that is otherwise too weak to be carried into the nervous system

pic n/a

Nocireceptor
A class of naked dendrites in the epidermis of the skin

interoreceptor
a sensory receptor that detects stimuli within the body, such as blood pressure and body position

Roots:

vitre-glass

tympan-a drum

sarco-flesh

sacc-a sack

omma-the eye

mechano-an instrument

coch- a snail

utric- a leather bag

tetan-rigid

rhodo-red

olfact-smell

ama-together

tropo-turn

noci-harm

stato-standing

gusta-taste

fovea- a pit

Graph from class:

This is an action potential graph. An action potential or impulse can only be generated in the axon of a neuron. When the neruon is stimulated the sodium channels open and sodium ions flood into the cell. As a response, potassium channels open allowing potassium ions to leave the cell. This rapid movement (the upward line in the graph) is called depolarization. As you can tell, this lasts a very short amount of time. The potassium pump respores the membrane to its original polarized condition by pumping sodium and potassium ions back to their original location. This period is called repolarization. When the potential drops back down it goes through short period of time called the refractory period during which the neuron can't respond to another stimulus. Once the potential levels out, the neuron has reached it's resting state.

Questions from Ch 46-48 Take Home

1) Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because

A) asexually reproducing organisms, but not sexually reproducing organisms, pass mutations to their offspring

B) More genetic variation is present in organisms that reproduce asexually than is present in those that reproduce sexually

C) sexually reproducing organisms can produce more offspring in a given time than can sexually reproducing organisms

D) asexually reproducing organisms devote more time and energy to the process of reproduction than do sexually reproducing organisms

E) asexually reproducing organisms have more dominant genes than organisms that reproduce sexually

2) The Small portion of the embryo that will become its dorsal side develops from

A) morula

B) primitive streak

C) gray crescent

D) blastocoel

E) archenteron

3) Action potentials move along axons

A) by reversing the concentration gradients for sodium and potassium ions

B) more rapidly in myelinated than in non-myelinated axons

C) by the direct action of acetylcholine on the axonal membrane

D) by activating the sodium-potassium "pump" at each point along the axonal membrane

E) more slowly in axons of large than in small diameter

Answers: 1) A 2) C 3)A

Related FRQ

http://www.collegeboard.com/prod_downloads/ap/students/biology/ap04_frq_biology_b.pdf

FRQ grading key

http://www.collegeboard.com/prod_downloads/ap/students/biology/ap04_sg_b_biology.pdf

Beginning Ch. 48

2009-04-21T03:57:00.007-06:00

An overview of the Nervous System

Sensory receptors collect information about the world outside the body as well as proscess information inside the body.

The Central Nervous System consists of the brain and the spinal cord. The conduction of signals from the central nervous system (CNS) to the effector cells is called motor output. Effector cells are target cells that produce some sort of response. They are generally gland or muscel cells.

The Peripheral Nervous System (PNS) consists of the nerves that commonicate motor and sensory signals in and out of the CNS. This reaches throughout the rest of the body. The PNS is divided into 2 groups

Somatic nervous system- directs contraction of muscles

Autonomic nervous system- controls organs and various involuntary muscles. broken into 2 parts

Sympathetic nervous system- involved in stimulation of activities that ready the body for action (for example increasing heart rate)

Parasympathetic nervous system- activates tranquil functions (stimulating secretion of saliva)

The Neuron is the functional unit of the nervous system. They are nerce cells. Neurons consist of 3 parts.

Cell body- contaqins the nucleus and other organelles

Dendrites- typically short, abundantly branched cell extensions that recieve incoming messages from other neurons

Axon- a single , long, slim extension of the cell body that sends nerve impulses. Covering most axons is a myelin sheath which insulates and protects it. At the end of an axon is a synaptic terminal which transmits signals to other neurons via neurotransmitters, or chemical messengers

There are 3 groups that neurons are classified in:

Sensory neurons- recieve initial stimulus Ex. those in the hand stimulated by touch
Motor neurons- stimulate effector cells Ex. those stimulating sweat glands to cool the body
Association neurons- located in the spinal cord or brain to recieve impulses from sensory neurons or send impulses to motor neurons. (aka interneurons)

The transmitting neuron is called the presynaptic cell and the recieving neuron is called the postsynaptic cell. Ganglia are clusters of nerve cells.

Reflex arc- a rapid involuntary response to a stimulus in which a sensory nerve recieves information and passes it along to the spinal cord and then to a motor neuron, which signals an effector cell.

Glial cells are support cells. They are necessary for the proper functioning of nerve cells, and perform different functions depending on the type of glial cell.

Astrocytes- provide support for neurons

Oligodgendrocytes- form myelin sheaths around axons in the CNS

Schwann Cells- form myelin sheaths around axons in the PNS

1. What are the basic building blocks of the brain?

A. brain cells

B. neurons

C. neurotransmitters

D. axons

2. What is most likely to be found in a synapse?

A. cells

B. neuron

C. neurotransmitters

3. Which is/ are true?

A. a neuron doesn't go through the cell cycle

B. a nephron transmits signals throughout the body

C. the 'fight or flight' response is atributed to the sympathetic nervous system

D. A & C

1. B ; 2. C ; 3. D

End of 46 and Beginning of 47

2009-04-16T14:23:00.008-06:00

End of 46
The egg cell is released into the oviduct, or fallopian tube, and cilia lining the fallopian tube convey the egg cell down to the uterus. The inner lining of the uterus is called the endometrium.

At the base of the uterus is cervix, which leads to the vagina, the canal through which a baby is born.

Spermatogenesis is the production of mature sperm cells, and it occurs in the seminiferous tubules. The cells that give rise to sperm are called spermatogonia. They undergo meiosis and differentiation eventually to form mature, motile sperm.

The head of the sperm is tipped with an acrosome, which secretes enzymes that help the sperm penetrate the egg.

Oogenesis is the development of mature ova. Oogonia are the cells that develop into ova; they multiply and begin meiosis, but they stop at prophase I of meiosis I. These egg cells are called primary oocytes, which are quiescent until puberty. From puberty onward, FSH periodically stimulates a follicle to grow and its egg cell to complete meiosis I and begin meiosis II. This forms the secondary oocyte.

At birth, a female’s ovaries contain about 1 million follicles, each with an ovum that has begun meiosis but is arrested in Prophase I of the first meiotic division.

At this stage, the ova are called primary ooctes. Some of these primary oocyte-containing follicles are stimulated to develop during each cycle.

During each follicular phase several follicles are stimulated to grow under FSH stimulation, but only be achieves full maturity as a tertiary, or Graafian, follicle by ovulation.

Graafian follicle

The primary oocyte completes the meiotic division during the follicular phase. Instead of forming two equally large daughter cells, however, it produces one large daughter cell, the secondary oocyte, and one tiny daughter cell, called a polar body.

Polar body formation

Thus the secondary oocyte acquires almost all of the cytoplasm from the primary oocyte (unequal cytokinesis), increasing its chances of sustaining the early embryo should the oocyte be fertilized.

The polar body disintegrates and the secondary oocyte then begins the second meiotic division, but its progress is arrested at Metaphase II. It is in this form that the egg cell is discharged from the ovary at ovulation, and it does not complete the second meiotic division unless it becomes fertilized in the fallopian tube.

Humans and other primates have menstrual cycles, and other mammals have estrous cycles. Menstruation occurs when the endometrium is shed from the uterus through the cervix and vagina.

The menstruation flow phase of the female cycle is the phase during which menstruation bleeding occurs.

The proliferative phase of the menstrual cycle is that during which the endometrium begins to regenerate and thicken.

In secretory phase, the endometrium continues to thicken, and is the embryo has not implanted in the lining by the end of this phase, menstruation flow occurs.

The ovarian cycle parallels the menstrual flow cycle, and begins with the follicular phase, in which several follicles begin to grow.

At the end of the follicular phase, ovulation occurs, during which the secondary oocycte is released from the ovary.

During the luteal phase of the ovarian cycle, endocrine walls in the corpus luteum secrete hormones.

Pregnancy (gestation) is the condition of carrying at least one embryo.

Start of 47 Animal Development

Animal Development: The stages of early embryonic development
After fertilization, there are three successive stages in early development

1. Cleavage which is a period of rapid mitotic cell division, partitions the cytoplasm of the zygote into smaller cells called blastomeres each which has its own nucleus.

Continued cleavage leads to a ball of cells called a morula, and then a fluid-filed central cavity called the blastocoel forms within the morula to produce a blastula.

2. Gastrulation is a drastic rearrangement of the cells in the blastula. In gastrulation, three (germ) cell layers are produced—ectoderm (later forms the nervous system and outer layer of skin). The endoderm (later develops to line the digestive tract). The mesoderm (later develops into most organs and tissues).

Multiple Choice Questions:

1. Storage and maturation of human sperm occur in the
A. Epididymis
B. interstitial cells
C. seminiferous tubules
D. sertoli cells
E. vas deferons

2. The function of the acrosome in the sperm head is to
A. provide ATP for flagellar movements
B. control DNA replication in the sperm
C. store enzymes used for penetrating the egg during fertilization
D. enclose the genetic material
E. provide a sharp head of the sperm to penetrate the egg

3. The dorsal lip of the blastopore induces development of the
A. trophoblast
B. mesoderm germ layer
C. mouth in deuterostomes
D. coelom
E. notochord

Answers: 1. A, 2. C , 3. E

Practice FRQ's

2009-04-15T19:01:00.003-06:00

Hello fellow students of biology!
I found some sites that have practice FRQ's for the exam. Hope they help! :)
http://www.csun.edu/~vceed002/biology/AP_biology/
http://apbio.biosci.uga.edu/exam/essays/
http://www.collegeboard.com/student/testing/ap/prep_free.html

2009-04-15T15:07:00.009-06:00

Video: http://videos.howstuffworks.com/hsw/24727-animal-reproduction-the-fertilization-of-an-egg-video.htm

Chapter 46

Mechanisms of Sexual Reproduction

Fertilization is the union of sperm and egg

External fertilization occurs when eggs are shed by the female and fertilized by the male outside the female's body

Internal fertilization occurs when sperm are deposited in the female reproductive tract and fertilization occurs within the tract

Gonads are the organs that produce gametes in most animals

Mammalian Reproduction

The Male:

The male's external reproductive organs are the scrotum and penis, and the internal organs are gonads (which produce gametes and hormones), accessory glands (which secrete necessary fluids), and ducts (which carry sperm and glandular secretions).

The testes are made up of many highly coiled tubules surrounded by connective tissue. The tubules are seminiferous tubules, the sites of sperm production. In between the tubules are Leydig cells, which produce testosterone and other androgens.

The testes are held in the scrotum (equivalent to the female labia majora), which is located outside the lower abdominal pelvic cavity

The sperm from the seminiferous tubules into the epididymis (where it is stored). During ejaculation, the sperm is propelled through the vas deferens, which ultimately meets up w/a duct from the seminal vesicle and forms an ejaculatory duct, which opens into the urethra (which serves as an excretory and reproductive duct)

The seminal vesicles, the prostate gland, and the bulbourethral gland all contribute secretions to create semen. These secretions which are usually alkaline supply necessary nutrients and a medium for the sperm cells

The penis is composed of three masses of spongy tissue derived from modified veins and capillaries

The Female:

The female gonads are the two ovaries. Each ovary contains many microscopic follicles. The ovaries secrete estrogen and progesterone

Follicles consist of one egg surrounded by one or more layers of follicle cells, which help to develop, nourish, and protect the egg cell. All of the follicles a woman has are formed before her birth. One follicle matures and releases its egg cell during each menstrual cycle

The follicle cells also produce estrogens, the female hormones

The egg cell is released from the follicle during ovulation. The remaining follicle tissue heals and grows in the ovary to form a body called a corpus luteum. This secretes estrogens and progesterone. Progesterone helps to maintain the uterine wall during pregnancy. If the egg cell isn't fertilized, the corpus luteum disintegrates

Multiple Choice Questions:

1. Why is sexual reproduction important?
A) It can result in numerous offspring in a short amount of time.
B) The resulting diverse phenotypes may enhance survival of a population in a changing environment.
C) It allows animals to conserve resources and reproduce only during optimal conditions.
D) It enables isolated animals to colonize a habitat rapidly.
E) Both A and D are important.

2. Which of the following is not required for internal fertilization?
A) internal development of the embryo
B) copulatory organ
C) sperm receptacle
D) behavioral interaction
E) All of the above are necessary for internal fertilization.

3. Why is internal fertilization considered more advantageous than external fertilization?
A) Usually fewer offspring are produced, so ample food supply is available.
B) The increased survival rate results in rapid population increases.
C) The smaller number of offspring often receive a greater amount of parental protection.
D) Usually a smaller number of genes are present, which promotes genetic stability.
E) The time and energy devoted to reproduction is decreased.

4. Internal and external fertilization both
A) produce a zygote.
B) occur in vertebrates.
C) occur in eutherian animals.
D) A and B only are correct.
E) A and C only are correct.

5. Which reproductive method is the most prevalent in mammals?

A) fragmentation

B) budding

C) regeneration

D) external fertilization

E) internal fertilization

6. The _______is (are) the site of testosterone production in the testis

A) seminiferous tubules

B) epididymis

C) Leydig cells

D) seminal vesicle

E) prostate gland

7. Which structure is part of the excretory and reproductive systems in males?

A) Ureter

B) Urethra

C) Seminal vesicle

D) Urinary bladder

E) Vas deferens

Answers:

1. B 2. A 3. C 4.D 5.E 6. C 7.B

Chapter 47 Vocab and Roots

2009-04-14T18:21:00.005-06:00

Hey guys, today in class we finished watching the movie, so I thought I'd post the vocab for us. This chapter is due on Thursday and we have Chapter 46 quiz tomorrow.

Chapter 47 Vocabulary and Roots

Primitive streak: A thickening along the future anterior-posterior axis on the surface of an early avian or mammalian embryo, caused by a piling up of cells as they congregate at the midline before moving into the embryo.

Notochord: A longitudinal, flexible rod made of tightly packed mesodermal cells, that runs along the anterior-posterior axis of a chordate in the dorsal part of the body.

Dorsal lip: The region above the blastopore on the dorsal side of the amphibian embryo.

Blastopore: In a gastrula, the opening of the archenteron that typically develops into the anus in deuterostomes and the mouth in protostomes.

Archenteron: The endoderm-lined cavity, formed during the gastrulation process, that develops into the digestive tract of an animal.

Gastrula: An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, and endoderm.

Holoblastic cleavage: A type of cleavage in which there is complete division of the egg; occurs in eggs that have little yolk (such as those of a sea urchin) or a moderate amount of yolk (such as those of the frog).

Meroblastic cleavage: A type of cleavage where there is incomplete division of yolk-rich egg, characteristic of avian development.

Chorion: The outermost of four extraembryonic membranes. It functions in gas exchange and contributes to the formation of the mammalian placenta.

Blastomeres: An early embryonic cell arising during the cleavage stage of an early embryo.

Yolk: Nutrients stored in an egg.

Vegetal pole: The point at the end of an egg in the hemisphere where most yolk is concentrated; opposite of animal pole.

Animal pole: The point at the end of an egg in the hemisphe

re where the least yolk is concentrated; opposite of vegetal pole.

Gray crescent: A light gray, crescent-shaped region of cytoplasm that becomes exposed after cortical rotation, located near the equator of an egg on the side opposite sperm entry, marking the future dorsal side of the embryo.

Morula: An embryo at an early stage of embryonic development, consisting of cells in a solid ball contained within the zona pellucid.

Blastocoel: The fluid-filled cavity that forms in the center of a blastula.

Blastula: A hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals.

Roots:
zona- a belt noto- the back arch-ancient
morul- a little mulberry involut-wrapped up blast-bud, sprout
cortex- shell fertil- fruitful gastro-stomach
holo- whole

Studying for the exam...

2009-04-14T18:10:00.001-06:00

Hey guys! I was wondering if anyone had a tips or tricks to memorizing the different types of isomers-- I keep getting them mixed up and I'm sure they will be on the exam. Thanks!

Hormones cont'd

2009-04-12T13:13:00.006-06:00

Insulin lowers glucose level by:
--promoting cellular uptake of glucose
--slowing glycogen breakdown in liver
--promoting fat storage

Glucagon increases blood glucose levels by:
--stimulating conversion from glycogen to glucose in the liver
--stimulating breakdown of fat and protein into glucose

The hypothalamus receives information from the nervous system and initiates response through the endocrine system.

Attached to the hypothalamus is the pituitary gland composed of the posterior and anterior

Oxytocin induces uterine contractions and the release of milk
--Suckling sends a message to the hypothalamus via the nervous system to release oxytocin, which further stimulates the milk glands
--This is an example of positive feedback, where the stimulus leads to an even greater response
--Antidiuretic hormone enhances water reabsorption in the kidneys

--A hormone can stimulate the release of a series of other hormones, the last of which activates a nonendocrine target cell; this is called a hormone cascade pathway

--A tropic hormone regulates the function of endocrine cells or glands

Follicle-stimulating hormone (FSH)

--Nontropic hormones target nonendocrine issues

--Two antagonistic hormones regulate the homeostasis of calcium (Ca2+) in the blood of mammals

Parathyroid hormone (PTH) is released by the parathyroid glands
Calcitonin is released by the thyroid gland

PTH increases the level of blood Ca
Calcitonin decreases the level of blood Ca

These notes are from Wednesday, April 8th

Chapter 46 Vocab!

2009-04-10T13:14:00.008-06:00

Here is Chapter 46 Vocab. Chapter 47 is also due next week but have a good long weekend everyone!

Organogenesis The process in which organ rudiments develop from the three germ layers after gastrulation.

Blastocyst The blastula stage of mammalian embryonic development, consisting of an inner cell mass, a cavity, and an outer layer, the trophoblast. In humans, the blastocyst forms one week after fertilization.

Cleavage (1) The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane. (2) The succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells.

Estrus The period of time which a female mammal is receptive to breeding.

acrosome A compartment in the head of the sperm that contains enzymes that allow the sperm to penetrate the protective layers of an egg.

spermatogenesis The continuous and prolific production of mature sperm cells in the testis.

gonad The male and female sex organs; the gamete-producing organs in most animals.

parthenogenesis Asexual reproduction in which females produce offspring from unfertilized eggs.

Zygote The diploid product of the union of haploid gametes during fertilization; a fertilized egg.

gamete A haploid reproductive cell, such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote.

asexual reproduction The generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts). In most cases, the offspring are genetically identical to the parent.

Roots:

bacul- a rod

blasto- produce

coit- a coming together

-ectomy= cut out

gyno- female

labi- lip

menstru- month

lact- milk

minor-smaller

Oo- egg

partheno- a virgin

-theca= a cup, case

partur- giving birth

Multiple Choice

1. Which is not a part of the sperm anatomy?

a) acrosome

b)mitochondria

c) trophoblast

2. What is implanted in the endometrium?

a)blastocyst

b)trophoblast

c)ovary

3. What is not a type of asexual reproduction?

a)fission

b)sexual reproduction

c)parthenogensis

4. T/F Oocytes is another word for eggs

5. T/F Menstrual cycles last on average 10 days.

Answers:

1. C 2. A 3. B

4. T 5. F

2009-04-07T19:32:00.002-06:00

Urine Formation

Filtration. The excretory tubule collects a filtrate from the blood. Water and solutes are forced by blood pressure across the selectively permeable membranes of a cluster of capillaries and into the excretory tubule.

Reabsorbtion. The transport epithelium reclaims valuable substances from the filtrate and returns then to the body fluids

Secretion. Other substances such as toxins and excess ions are extracted from the body fluids and added to the contents of the excretory tubule

Excretion. The altered filtrate (urine) leaves the system

In the human kidney, most of the nephrons are cortical nephrons, these are in the renal cortex. The rest are juxtamedullary nephrons, with long loops of Henle that extend into the renal medulla

Capillaries called afferent arterioles are associated with the nephrons, and as they leave the glomerulus, the capillaries converge into an efferent arteriole. This vessel subdivides again to form peritubular capillaries which surround the proximal and ditstal tubules.

There are Five Main Steps in the Transformation of Blood Filtrate to Urine

1.) In the proximal tubule, secretion and reabsorbtion changes the volume and composition of the filtrate. The pH of body fluids is controlled and bicarbonate is absorbed as are NaCl and water.
2.) In the descending loop of Henle, reabsorbtion of water continues
3.) In the ascending loop of Henle, the filtrate loses salt without giving up water and becomes more dilute.
4.) In the distal tubule, K+ and NaCl levels are regulated, as is filtrate pH
5.) The collection duct carries the filtrate though the medulla to the renal pelvis and the filtrate becomes more concentrated by the movement of salt.

Antidiuretic hormone is an important hormone in the regulation of water balance. It is the product in the hypothalamus and stored in and released from the pituitary gland. Two other hormones involved in regulation of water balance are angiotensin and aldersterone.

Chapter 45: Hormones and the Endocrine System

The Body’s Long-Distance Regulators

Animal hormones are chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body.

Hormones reach all parts of the body, but only target cells are equipped to respond

Two systems coordinate communication throughout the body: the endocrine system and the nervous system

The endocrine system secretes hormones that coordinate slower but longer-acting responses including reproduction, development, energy metabolism, growth and behavior.

Types of Secreted Signaling Molecules

Secreted chemical signals include:
• Hormones
• Local regulators
• Neurotransmitters
• Neurohormones
• Pheromones

Endocrine glands are ductless and secrete hormones directly into surrounding fluid

Exocrine glands have ducts and secrete substances onto the body surfaces or into body cavities (for example, tear ducts)

Local regulators are chemical signals that travel over short distances by diffusion

Pheromones are chemical signals that are released from the body and used to communicate with other individuals in the species

Binding of a hormone to its receptor initiates a signals transduction pathway leading to responses in the cytoplasm, enzyme activation, or a change in gene expression

Insulin and Glucagon: Control of Blood Glucose

Insulin and glucagon are antagonistic hormones that help maintain glucose homeostasis

The pancreas has clusters of endocrine cells called islets of Langerhans with aloha wells that produce glucagon and beta cells that produce insulin.

Multiple Choice

1) Loop of Henle is concerned with:
A. excretory system
B. reproductive system
C. nervous system
D. muscular system

2) Glucose is reabsorbed in the kidney mainly by
A. Bowman's capsule
B. Loop of Henle
C. Proximal Convoluted Tubule
D. Distal Convoluted Tubule

3) In the kidney the correct sequence of formation of urine involves the following processes:

A. glomerular filtration, reabsorption, tubular secretion
B. reabsorption, filtration, secretion
C. filtration, secretion, reabsorption
D. reabsorption, secretion, filtration

4) In the distal convoluted tubule of the nephrons

A. Sodium reabsorption requires energy
B. Secretion of potassium does not require energy
C. Water reabsorption requires energy
D. Ammonia is secreted

5) All of the following statements about hormones are correct except:

A. They are carried by the circulatory system.
B. They are used to communicate between different organisms.
C. They elicit specific biological responses from target cells.
D. They are produced by endocrine glands.
E. They are modified amino acids, peptides, or steroid molecules.

ANSWERS: 1) A 2) C 3) A 4) A 5) B

Marine and Insect videos

2009-04-07T10:50:00.002-06:00

In case I traumatized some of you yesterday with the insect and marine videos, I wanted to give you the link where Isabella Rosselini discusses why she chose to create these films. She sat down and spoke on NPR.

http://www.npr.org/templates/story/story.php?storyId=102750943

Enjoy,
Mrs. Lyon

Chapter 44 Wrap Up!

2009-04-06T20:45:00.003-06:00

Hello Biology B and C Block!

So, today we took a vocab quiz, took notes, and yes, watched a porno. I'd say it was a productive class!

Here are the notes we took today...

Mammals have two kidneys and each is supplied with a renal artery and renal vein. Urine leaves the kidneys through the ureters, which drain into the urinary bladder. Urine is expelled from the body through the urethra.

Nephrons are made up of a single long tubules and the glomerules, a ball of capillaries. At the end of the tubule is the Bowman's capsule, a C-shaped capsule that surrounds the glomerulus.

The filtrate flows through the proximal tubule, the descending loop of Henle, the loop of Henle, the ascending loop of Henle, and the distal tubule. The distal tubule empties into a collecting duct, which recieves wastes from many nephrons. The filtrates empties into the renal pelvis

So that should catch anyone up on the notes they might have missed!

1. Which process in the nephron is least selective?

a. Filtration

b. Reabsorption

c. Active transport

d. Secretion

e. Salt pumping by the loop of the Henle

2. Urine formed by a kidney collects in the ____ before being drained from the kidney by the ____ and transported to the ______.

a. Urethra, urinary bladder, ureter

b. renal pelvis, medulla, cortex

c. renal pelvis, ureter, urinary bladder

d. renal pelvis, urethra, urinary bladder

e. ureter, renal pelvis, urinary bladder

3. The ____ are the major blood vessels transporting blood to the kidneys

a. pulmonary arteries

b. glomerulus

c. renal arteries

d. renal veins

e. venae cavae

4. The outer part of the kidney is the _____.

a. Medulla

b. Nephron

c. Lacteal

d. cortex

e. Bowman's capsule

5. Which of these is the functional unit of a kidney?

a. Neuron

b. Villi

c. Nephron

d. Alveolus

e. osteon

ANSWERS: A, C, C, D, C

Here is an FRQ on symbiotic relationships you can use as a refresher!

Organisms rarely exist alone in the natural environment. The following are five examples of symbiotic relationships.

Plant root nodules

Digestion of Cellulose

Epiphytic plants

AIDS

Anthrax

Choose FOUR and,

a) Identify the participants involved in the symbiosis and describe the symbiotic relationship

b) Discuss the specific benefit or detriment, if any, that each participant recieves from the relationship.

I thought this one was really hard and yes this was actually on an exam! Kinda scary... so starting to review now is a good idea!

Have a great night!

2009-04-06T00:30:00.002-06:00

Chapter 44: Osmoregulation and Excretion

An Overview of Homeostasis

Homeostasis refers to the animals ability to regulate its internal environment. Thermoregulation refers to how animals maintain their internal temperature, and osmoregulation refers to how they regulate solute balance and water content.

The digestion and utilization of proteins creates the greatest need for osmoregulation in the kidneys

Thermoregulation takes place through the following processes.
1) The adjustment of the rate of heat exchange between the animal and its environment—through insulating hair, feathers, and fat—is accomplished through vasodilation (an increase in diameter of blood vessels at the skin, which cools the blood) or vasoconstriction (to opposite of vasodilation)
2) Evaporation across the skin (through panting or sweating)
3) Behavioral responses (changes in location of posture)
4) Alteration of the rate of metabolic heat production (only in endoderms).

Mammals and birds are endothermic, whereas amphibians and reptiles are Ectothermic. Fishes and aquatic invertebrates are conformers—that is, they live in relatively stable environments and can accommodate some slight change in body temperature if the environment is altered.

Water Balance and Waste Disposal

Most metabolic wastes must be excreted from the body. One of the most important waste products are nitrogen-containing breakdown products of proteins and nucleic acids.

Enzymes remove nitrogen from these compounds to creat ammonia. Some animals excrete ammonia directly into water, where it becomes diluted. Others convert it first to urea in the liver, where ammonia is combined with carbon dioxide in an endergonic reaction or to uric acid. Uric acid is more energetically expensive to produce, but it is insoluble in water and can be excreted as a paste or crystals.
Excretory Systems

Most excretory systems produce urine in a two step process. First the body fluid (blood or hemolymph) is collected, and then the composition of the fluid is is adjusted by selective reabsorbption of solutes

Insects and terrestrial arthropods like the grasshopper have Malpighian tubules that remove nitrogenous wastes. The open into the digestive tract and dead-end at points in the hemolymph. The tubules secrete nitrogenous wastes and salts into the lumen, and water follows by osmosis.

Mammals have two kidneys, and each is supplied with a renal artery and a renal vein. Urine leaves the kidneys through the ureters, which drain into the urinary bladder. Urine is expelled from the body through the urethra.

The kidney has two regions, the outer renal cortex and the inner renal medulla. These two regions are packed with nephrons which are functional units of the kidneys

Multiple Choice Questions
1. Of the mechanisms by which organisms exchange heat with their surroundings, which one results in only loss of heat from the organism?
A) convection
B) metabolism
C) radiation
D) conduction
E) evaporation

2. Which of these vertebrates are endotherms?
A) birds
B) bony fishes
C) cartilaginous fishes
D) amphibians
E) reptiles

3. Which of the following assertions about regulation of body temperature is correct?
A) Ectothermic animals are cold-blooded.
B) Most animals are endotherms.
C) Insects are always ectothermic.
D) Endothermy involves production of heat through metabolism.
E) Mammals are always ectothermic.

4. All of the following are mechanisms of thermoregulation in terrestrial mammals except
A) changing the rate of metabolic heat production.
B) changing the rate of evaporative loss of heat.
C) changing the rate of heat exchange by anhydrobiosis.
D) relocating to cool areas when too hot or to warm areas when too cold.
E) changing the rate of heat loss by vasodilation and vasoconstriction.

Answers:
1. E
2. A
3. D
4. C

Notes from 4/2/09

2009-04-03T16:19:00.005-06:00

Hey guys, sorry I couldn't get these up yesterday, my computer wouldn't upload the notes. But here are the notes we took in class yesterday:

B-cell receptors bind intact antigens.

T-cell receptors bind antigens that are displayed by antigens-presenting cells (APCs) on their MHCs.

MHCs (Major histocompatability complex molecules) are proteins that are the product of a group of genes.

There are two types of MHCs:

1. Class I MHCs are found on almost all cells of the body, except RBCs

2. Class II MHCs are made by dendritic cells, macrophages and B cells

The specificity of B and T cells is a result of the shuffling and recombination of several gene segments and results in more than 1 million different B cells and 10 million different T cells.

Each B or T cell responds to only one antigen.

A primary immune response occurs when the body is first exposed to an antigen and lymphocyte is activated.

A secondary immune response occurs when the same antigen is encountered at later time. It is faster and of greater magnitude.

Acquired immunity defends agaisnt infection of body cells and fluids.

Acquired immunity has two branches:

1. Humoral immune response involves the activation and clonal selection of effector B cells which produce antibodies that circulate in the blood.

2. Cell-mediated immune response involves the activation and clonal selection of cytotoxic T cells, which identify and destroy infected cells.

Helper T-cells aid both responses. When activated by interaction with the class II MHC molecule of an APC, they secrete cytokines that stimulate and activate botth B cells and cytotoxic T cells. The helper T cell is bound to the class II MHC by a CD4 protein.

Cytotoxic T cells bind to Class I MHC molecules displaying antigenic fragments on the surface of infected body cells. The cytotoxic T cell is bound to the infeced cell's class I MHC by its CD protein. Cytotoxic T-cells destroy infected body cells.

Mammalian immune system sequence of encountering a pathogen:

1. Antigenic determines from pathogen bind to antigen receptors on lymphocytes.

2. Lymphocytes specific to antigentic determinants from pathogen becomes humerous.

3. Lymphocytes secrete antibodies.

4. Pathogen is destroyed.

5. Only memory cells remain.

A simple and hopefully humerous cartoon of the immune system response:

This is a link to a short animation of the Antibody immunity response to Pathogens, there are not words, but it have some good graphics:

http://www.youtube.com/watch?v=lrYlZJiuf18&feature=related

And now for some multiple choice questions:

1. In the inflammatory response, which one of these components would not allow the rest to happen if it did not occur?

A) Increased population of phagocytes in the area
B) Leakage of plasma to the affected area
C) Release of histamine
D) Dilation of arterioles
E) Increased permeability of blood vessels

2. Histamine’s main goal is to:

A) Destroy white blood cells.
B) Attract T cells.
C) Dilate blood vessels.
D) Phagocytize pathogens.
E) Decrease blood flow.

3. _________ interacts with the antigen-class II MHC complex presented by macrophages.

A. B cells
B. Bacterial cells
C. Helper T cells
D. Epithelial cells
E. Cytotoxic T cells

4. Clonal selection is the division of ___________ that have been stimulated by binding to an antigen, which results in the production of cloned ____________.

A. helper T cells ... plasma cells
B. B cells ... plasma cells and memory cells
C. T cells ... B cells
D. B cells ... macrophages
E. macrophages ... B cells and T cells

ANSWERS:

1. c 2. c 3. c 4. b

Ch. 43 Vocab and Roots

2009-04-01T11:16:00.009-06:00

Chapter 43 Vocabulary

Phagocytosis: A type of endocytosis in which large particulate substances are taken up by a cell. It is carried out by some protests and by certain immune cells of animals.

Lysozyme: An enzyme that destroys bacterial cell walls; in mammals, fount in sweat, tears, and saliva.

Neutrophil: The most abundant type of white blood cell. Neutrophils are phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.

Interferons: A protein that has antiviral or immune regulatory functions. Interferon alpha and interferon beta, secreted by virus-infected cells, help nearby cells resist viral infection; interferon-y, secreted by T cells, helps activate macrophages.

Histamine: A substance released by mast cells that causes blood vessels to dilate and become more permeable inflammatory and allergic responses.

Natural Killer (NK) Cell: A type of white blood cell that can kill tumor cells and virus-infected cells as part of innate immunity.

Epitope: A small accessible region of an antigen to which an antigen receptor or antibody binds; also called an antigenic determinant.

Antigen: A macromolecule that elicits an immune response by binding to receptors of B cells or T cells.

Effector Cell: A lymphocyte that has undergone clonal selection and is capable of mediating an acquired immune responses.

Memory Cell: One of a clone of long-lived lymphocytes, formed during the primary immune responses, that remains in a lymphoid organ until activated by exposure to the same antigen that triggered its formation. Activated memory cells mount the secondary immune response.

Clonal Selection: The process by which an antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen. The selected lymphocytes proliferate and differentiate into a clone of effector cells and a clone of memory cell specific for type stimulating antigen.

Helper T Cell: A type of T cell that, when activated, secretes cytokines that promote the response of B cells (humoral response) and a cytotoxic T cells (cell-mediated response) to antigens.

Immunization: Generating a state of immunity by artificial means. In active immunization, vaccination, a weakened form is administered. In passive, Antibodies specific for a particular microbe are administered temperorary protection.

Humoral Immunity: The branch of acquired immunity that involves the activation of B cells and that leads to the production of antibodies which defend against bacteria and viruses in body fluids.

Cell Mediated Immunity: The branch of acquired immunity that involves the activation of cytoxic T cells, which defend against infected cells.

Monoclonal Antibodies: Any of a preparation of antibodies that have been produced by a single clone of cultured cells and thus are all specific for the same epitope.

Agglutination: The clumping of cells (bacteria, red) in the presence of an antibody. Creates a large complex and prevents foreign material from entering.

Anaphylactic Shock: Occurs when an allergic response triggers a quick release from mast cells of large quantities of immunological mediators (histamines, prostaglandins, leukotrienes) leading to a drop in blood pressure and difficulty breathing.

Basophils: A type of white blood cell in the circulation IEG surface, release chemical mediators causing IEG to bind to a specific allergen.

Roots

Agglutnat—glued together
Immuno—safe, free
Perfora—bore through
Pyro—fire
Neutro—neutral

Multiple Choice Questions

1. Which cells and which signaling molecules are responsible for initiating an inflammatory response?

A. phagocytes: chemokines
B. phagocytes:lysozymes
C. mast cells:histimines
D. dendritic cells:interferons
E. lymphocytes:interferons

2. Memory Cellls

A. Produce cyclosporine
B. Are responsible for passive immunity
C. prevent an animal from encountering certain antigens
D. provide an accelerated immune response upon second exposure to a particular antigen
E. All of the above

3. The inflammatory response includes all of the following except

A. vessel constriction
B. temperature increase
C. increased blood flow
D. phagocyte attack
E. all of the above

Answers: 1. c 2. d 3. a

Things Due Tomorrow

Chi Square Analysis
Invertebrate Activity
Invertebrate Takehome
Ch. 43 Vocab
Ch. 43 Vocab Quiz

Introduction to Animals Packet Vocab

2009-03-31T20:59:00.008-06:00

Grade: group of animal species that share the same level of organizational complexty.

Body Plan: the set of morphological and development traits that define a grade (level of organizational complexity).

Radial Symmetry: characterizing a body-shaped like a pie or barrel with many eqaul parts radiating outward like the spokes of a wheel; present in cnidarians and echindoerms; also can refer to flower structure.

Bilateral Symmetry: characterizing a body form with a central longitudinal plane that divides the body into two eqaul parts but opposite halves.

Dorsal: pertaining to the back of a bilaterally symmetrical animal.

Ventral: pertaining to teh underside, or bottom, of a bilaterally symmetrical animal.

Anterior: the head end of a bilaterally symmetrical animal.

Posterior: rear, or tail end, of a bilaterally symmetrical animal.

Cephalization: An evolutionary trend toward the concentration of sensory equipment on the anterior end of the body.

Germ Layers: three main layers that form the various tissues and organs of an animal body.

Endoderm: inmost of the three main layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract.

Diploblastic: having two germ layers.

Triplobalstic: three germ layers, the endodoerm, meso0derm, and ectoderm.

Mesoderm: the middle priamry germ layer of an early embryo tht develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system.

Body Cavity: a fluid-containing space between the digestive tract and the body wall.

Coelom: a body cavity completely lined with mesoderm.

Pseudocoelomate: an animal whose body cavity is not completely lined by mesoderm.

Coelomate: animal that possesses a true coelom (fluid- filled body cavity lined by tissue completely derived from mesoderm).

Acoelomate: a solid-bodied animal lacking a cavity between the gut and outer body wall.

Ventral side of a star fish

The three Germ Layers

The Body Caivty

Radial and Bilateral Symmetry

Porifera:

- Example: sponges

- Characterisitics: no true tissue, suspension feeders

Cnidaria:

-Example: corals, jelltfish, and hydra

-Characteristics: gastrovascular cavity, mouth and anus

Rotifera:

-Characterisitics: microscopic size, organ systems, alimentry canal, feed on micororganisms

Annelid:

-Example: earthworms

- Characteristics: segemted worms

Platyhelminthes:

-Examples: flatworms, tapeworms, and flukes

- Characteristics: bilateral symmetry, central nervours system, no body cavity, no organs

Arthropoda:

-Examples: insects, crustaceans, and arachnids

- Characterisitics: segemnted exoskeleton, jointed appendages

Mollusca:

-Examples: snails, clams, squids, and octupuses

- Charaterisitics: soft body, hard shell

Echinderms:

-Examples: sand dollars, sea stars, and sea urchins

- Charactersitics: radial symmetry, internal canals

Nematod:

-Example: roundworm

- Charactersitics: tough cucticle, tubular

Review Quiz Questions:

1. Acoelomates are characterized by...?

-a. the absence of a brain

-b. the absence of mesoderm

-c. deuterostome development

-d. a coelom that is not completely lined with mesoderm

-e. a solid bodt without a cavity surrounding internal organs

2. Which of the following subdivisions of the animal kingdom encompases all the other in the list...?

-a. protostomis

-b. bilateria

-c. radiata

-d. eumetazoa

-e. deuterostomia

3. A land snail, a clam, and an octupus all share...?

-a. a amntle

-b. a radula

-c. gills

-d. embryonic torsion

-e. distinct cephalization

Answers:

1. e, 2. d, 3. a

Created By Alyssa Hamilton

Invertebrate phylums and their characteristics

2009-03-30T21:31:00.002-06:00

Hi everyone, so this is a short blurb about invertebrates and their phylum s.

So, as Campbell states, the "Kingdom Animalia encompasses 1.3 million known species, and estimates of total species range far higher".

Invertebrates - animals without a backbone - account for 95% of known animal species and all but one of the roughyl 35 animal phyla that have been described.

More than a million extant species of animals are known, and at least as many more will probably be identified by future biologists.
Invertebrates inhabit nearly all environments on Earth, from the scalding water of deep-sea hydrothermal vents to the rocky, frozen ground of Antarctica.

The three main taxons of the invertebrates are: LOPHOTROCHOZOANS, ECDYSOZOA and the DEUTEROSTOMIA taxon, and there is great diversity amongst them.

Lophotrochozoan is defined as: a member of a group of animals phyla identified as a clade by molecular evidence. Lophotrochozoans include organisms characterized by lophophores or trochophore larvae. ('Lophophores' are feeding organs.)

Within the lophotrochozoans are the phyla:

Platyhelminthes (20,000 species)

2. Rotifera (1,800 species)

Ectoprocta (4,500 species), Brachiopoda (335 species), Acanthocephala (1,100 species), Cycliophora (1 species), and Nemertea (900 species).

Then there is the taxon ECDYSOZOA, which is defined as a member of a group of animal phyla identified as a clade by molecular evidence. (Many ecdysozoans are molting animals.) The ecdysozoa taxon includes the phyla Loricidera (10 species), Priapula (16 species), Tardigrages (800 species), Onychophora (110 species), Nematoda (25,000 species), and Arthropoda (1,000,000 species).

The taxon deuterostomia is a superphylum of animals. They are distinguished by their embryonic development; in deuterostomes, the first opening (the blastopore) becomes the anus, while inprotostomes it becomes the mouth. This includes the phyla Hemichordata (85 species), Echinodermata (7,000 species), and Chordata (52,000 species).

Here are some pictures of a variety of invertebrates that are beneficial in our ecosystem today.

Questions:

1. Which phylum is characterized by animals that have a segmented body?
a. Cnidaria
b. Platyhelminthes
3. Silicea
4. Arthropoda
5. Mollusca

2. Cnidarians are _(a)_ that often use tentacles arranged in a ring around their mouth to capture prey and push the food into their gastrovascular cavity.
a. omnivores
b. carnivores
c. herbivores

3. Which of the following characteristics is probably most responsible for the great diversification of insects on land?
a. exoskeleton
b. bilateral symmetry
c. segmentation
d. antennae
e. eyes

Answers: 1 d, 2b, 3a.

Chapter 42 (extra notes)

2009-03-27T11:43:00.003-06:00

Okay so in class on March the 19th we went over our take home quiz on Chapters 40,41, and 42, also we started on the packet of the Chi square, also the Invertebrate Activity.
Also I found this awesome video that describes all of the notes we took on 42. It doesn't get into great detail but it gives a great outline on the notes.

http://www.youtube.com/watch?v=4isM9FUBXxQ

Few extra notes on Circulation and Gas Exchange:

All animal cells go through cellular respiration, which is the breakdown of energy into a usable form to provide power to perform cellular functions. Oxygen is required for that of cellular respiration, resulting in carbon dioxide as a waste product. Animals, therefore, use an organ system in which the exchange of oxygen and carbon dioxide can take place with the external environment, as well as a system to transport these gases throughout the body. The respiratory and circulatory systems perform these two intertwined tasks. The respiratory system exchanges gases with the environment, while the circulatory system transfers those gases throughout the body.

All gas exchange requires a moist medium for the gases to move from surface to surface. This requirement poses no problem for animals living only in aquatic environments, as gills and skin absorb gases directly from the surrounding water. However, as animals evolved to live on land, they developed tracheae and lungs that contained moist surfaces for this purpose. The following table describes each respiratory structure in more detail.

Skin	In a process known as cutaneous respiration, the skin, which is moist and well-vascularized, exchanges gas directly with the environment through its blood vessels.	Amphibians, such as frogs and salamanders, as well as some marine snakes, respire through their skin. This usually takes place in conjunction with respiration through lungs.




Gills	Gills are extensions of internal tissues that project into the water, where gases can diffuse. Gills are heavily branched, providing a large amount of surface area for gas to exchange, making them more efficient than skin. Gills can be external (not enclosed in the body), which requires constant movement to ensure contact with fresh water, or internal, enclosed within branchial chambers where water is pulled in and out, creating currents over the gill tissue.	External gills are found on the larvae of many fish and amphibians, as well as adult amphibians such as the axolotl. Internal gills are found in arthropods such as crustaceans and spiders, mollusks, echinoderms many adult amphibians, and fish.

Tracheae	Tracheae are air-filled tubular passages that form an extensive network in the body. These passages connect the body surface with all internal structures. Oxygen is passed straight from the tracheae into cells. Insects rely solely on this respiratory system, rather than a circulatory system, to transfer oxygen throughout their bodies. Insects have external structures on their exoskeleton called spiracles that open and close to prevent water loss during respiration.	Tracheae are the respiratory system of most terrestrial arthropods, including all insects, some spiders, mites and ticks, millipedes, and centipedes.

Lungs	Air moves into and out of the body through branched tubular passageways, which moisten the air in the process. Eventually moist air reaches a thin, wet membrane that permits exchange of gases within the lungs, where it can be circulated throughout the body.	Lungs are found in some arthropods, as well as all amphibians, reptiles, birds, and mammals.

1. As blood returns to the human heart from systemic capillaries, the blood will first enter the:
A. left atrium

B. right atrium
C. left ventricle

D. right ventricle

E. aorta

2. Which of the following are the only vertebrates in which blood flows directly from respiratory organs without first returning to the heart?
A. Amphibians

B. Birds

C. Fishes
D. Mammals

E. Reptiles

3. Tracheal systems with gas exchange are found in:
A. crustaceans

B. earthworms

C. insects
D. jellyfish

E. vertebrates

Answers: 1: B,2:C,3:C.

2009-03-18T14:16:00.002-06:00

Chapter 42 (Continued)
The complete cycle of contraction and relaxation of the heart is called the cardiac cycle. The contraction phase is called systole, and the relaxation phase is called diastole.Heart rate is the rate of contraction per minute, and the stroke volume is the amount of blood pumped by the left ventricle during each contracion.

There are four heart valves and two atrioventricular (AV) valves between each atrium and ventricle, which prevent the back flow of blood into the atria; there are also two semiulnar valves-one located at the entrance to pulmonary artery and the second at the entrance to the aorta.Regulation of the Heartbeat
The sinoatrial (SA) node is the pacemaker of the heart. It is located in the upper wall of the right atrium. It stes the rate at which cardiac muscle cells contract.The AV or atrioventrical node, located in the lower wall of the right atrium, delays the impulses from the SA node to allow the atria to completely empty before the ventricles contract.

The Lymphatic System and Blood
The lymphatic system is responsible for returning lost fluid and proteins from the blood back into the blood. Lymph is the lost fluid and proteins carried in the lymphatic system. Along a lymph vessesl are lymph nodes that filter lymph and attack viruses and bacteria, playing and important role in immunity.
Blood is actually a connective tissue made up of many kinds of cells in a liquid matrix called plasma. Plasma is mosly water, but it also contains ions, electrolytes, and plasma proteins. It also carries nutrients. Metabolic wastes gases and hormones.
In addition, blood plasma maintains the blood osmotic pressure and carries:
1. red blood cells (RBC) (erythrocytes)-which transport oxygen vea hemoglobin (an
iron containing protein), transport of water soluble lipids

2. white blood cells (WBC) (leukocytees)- which are part of the immune system
3. platelets- are fragments of cells that are responsible for blood clotting and immune reponses
Blood contains a soluble plasma protein called fibrinogen, which forms clots when it is converted to its active form, fibrin
Blood clotting involves:
-the activation of prothrombin and thrombin
-adhesion of platelets
-clottin factor releases by clumped plateletsQuestions
1. Heart rate is
a. the amount of blood pumped by the left ventricle during contraction
b. the contraction phase also called systole
c. the rate of contraction per minute
d. the relaxation pase also called diastole

2. Plasma is
a. mostly water
b. carrie white blood cells
c. carries red blood cells
d. carries platelets
e. All of the above

3. Fibrinogen is
a. protein involved in coagulation
b. network of capillaries in a tissue or organ
c. liquid matrix of blood in which the cells are suspended
d. iron-containing protein in red blood cells

Answers:
1.c
2. e
3. d

Chapter 41 continued../Chapter 42

2009-03-17T17:23:00.006-06:00

-The large intestine, also called the colon, is connected to the small intestine by a sphincter. The point of the connection is the site of the cecum, a small pouch with an extension called the appendix.
-The main function of the large intestine is to compact waste and recover water from it that can be returned to the body. The wastes become more solid as they travel along and form feces.
-At the end of the colon is the rectum, where feces are stored until they are eliminated.
-Evolutionary adaptions of vertebrate digestive systems correlate with diet.
-A mammal's dentition is generally correlated with its diet. In particular, mammals have specialized dentition that best enables them to ingest their food.
-Herbivores generally have longer alimentary canals. carnivores, reflecting the longer time needed to digest vegetation. Much of the chemical energy in herbivore diets comes from the cellulose of plant cell walls Many vertebrates (as well as termites) house large populations of symbiotic bacteria and protists whose enzymes actually digest the cellulose.

Chapter 42: Circulation and Gas Exchange:

-Both open and closed circulatory systems have blood (a circulatory fluid). Vessels (tubes through which blood moves), and a heart (a structure that pumps the blood).
-In open circulatory systems, blood bathes the organs directly. The blood and lymph combined are called hemolymph, and a heart pumps hemolymph into cavities called sinuses.
-In closed circulatory systems, blood is contained within vessels and pumped around the body; the blood is separated from the interstitial fluid.

-Humans have a closed circulatory system called the cardiovascular system. The heart has atria (chambers that receive blood returning to the heart) and ventricles (chambers that pump blood out of the heart).
-The main types of blood vessels in humans are the arteries, veins, and capillaries. Arteries carry blood away from the heart and branch into smaller arterioles. Then capillaries network to form capillary beds. These capillary beds converge into venules, which converge into veins, which carry the blood back to the heart.
-Fluid flows into capillary bed at the upstream end near an arteiole and out of a capillary at the downstream near a venule.
-Velocity of blood flow is lowest in the capillaries.

-Here are the steps of double circulation in mammals:
1. The right ventricle pumps blood to the lungs through the pulmonary arteries.
2.The blood floes through capillary beds in the lungs and picks up oxygen and relases CO2.
3. The blood returns to the left atrium of the heart via pulmonary veins.
4. Then it continues to the left ventricle.
5. Then it leaves the heart via the aorta, which sends bloos to the arteries throught the body.
6. The blood enters the capillary beds in the neck, head, and arms.
7. The blood enters capillary beds in the abdomen and legs, giving up oxygen and picking up CO2 from cell respiration.
8. The capillaries form the venules, and the blood from the neck, head and arms travels back to the veins and back to the right atrium via the anterior vena cava.
9. Blood from the legs and trunk travels through the posterior vena cava back to the right atrium.
*KNOW THIS FROM ANY STARTING POINT!*

Questions:

1. Which blood vessel is thicker?
a) arteries
b) veins
c) capillaries

2. Which type of blood vessels carries blood away from the heart?
a) veins
b) arteries
c) capillaries
d) all of the above

3. Which is the organ that pumps blood throughout the human body?
a) the lungs
b) the heart
c) the kidneys
d) blood vessels

Answers:

1. a.
2. a *tip: to help you remember that just think AA arteries-away*
3. b. i think you should know that by now.

Mnemonic Study List for AP Bio Review

2009-03-17T10:46:00.000-06:00

AP BIO MNEMONIC LIST

UNIT I – Chemistry

FOR ORGANIC MOLECULES

1) Clean Later Party Now
Carbohydrates
Lipids
Proteins
Nucleic Acids

2) Mono-Zach-and Cody ride in a Car (monosacharides make up carbohydrates)
Lipids-- I tell them to think of A. Jole and what are her lips filled with? fat--fatty acids
Proteins-- Proteams are Mean, also when you eat ribs you get protein (ribosomes make proteins)

FOR SOLUTIONS:
I tell my kids that I'm a guy playing a lute and I'm getting sucked into the vent. Solute into solvent

FOR OXIDATION AND REDUCTION:

1) LEO (the lion) says GER
LEO- loss of electrons is oxidation
GER- gain of electrons is reduction

2) OIL RIG
Oxidation is loss, reduction is gain

FOR CATIONS AND ANIONS:
1) Cations are pawsitive, anion stands for "a negative ion".

2)cation = notice the positive sign in the middle of the word.
anion = notice that the "an" sounds like the "n" in negative.
UNIT II – Cells

FOR THE TAXA:
1) Kings Play Chess on Fiber Glass Stools
2) domain, kingdom, phylum, class, order, family, genus, species=
Did King Phillip come over for good steak?
3) King Paul Ordered some Funky Green Spinach (Kingdom, Phylum, Order Family Genus, Species)
4) Kinky People Cry Out For Good Sex.
5) "Kids playing catch on freeways get squished" - so now I pass this on to my students. I always tell them that I also learned it when I was their age.
Now, I just add "DUMB kids..." (for domain at the beginning!!).

FOR PHOTOSYNTHESIS AND CELLULAR RESPIRATION

1) N-A-D and F-A-D take H and e to the E-T-C to make A-T-P.

2) NADPH or NADH? THe P stands for photosynthesis (Ok, I know it really doesn't but the never mix the two up after this!)

FOR OSMOSIS:

1) In a hypOtonic solution, the cell will swell up like an "O"

2) When a cell is in a hypOtonic solution, it swells up like a balloon (O-shaped) and the cell cries out "OOOOOOHHHHHH!" as it is about to explode. when a cell is in a hypERRRRtonic solution, it shrivels and moans "ERRRRRR."

3) Hypo sounds like hippo; Hippo's are fat, and if they get too fat they will pop. I would silently repeat the phrase: Hypo, hippo, fat, pop, before answering any questions on the distinction between these two definitions.

4) Hypertonic solutions, have a high concentration of solutes, like sugar makes you hyper.
FOR CELL CYCLE

1) For mitosis, I made up a song in the shower one day to the tune of YMCA; the kids even get up and make their arms into P - M - A -T
YOUNG CELL/ WELL YOU HAVE TO GROW UP
UNTIL YOUR SA/ TO VOLUME RATIO’S TOO SMALL
and THEN YOU/ MUST DIVIDE OR YOU’LL DIE
SO YOU’LL UN-DER-GO MI-TO-SIS
G1/ S AND FINALLY G2
DOUBLING NUCLEUS/ AND THE CELL CONTENTS TOO
AND THEN YOU/ WILL BEGIN TO DIVIDE
SO YOU’LL UN-DER-GO MI-TO-SIS
HEY, HEY, HEY, HEY, HEY
OH YES A CELL MUST GO THROUGH
P M A T
OH YES A CELL MUST GO THROUGH
P M A T
PROPHASE AND MET-A-PHASE
AN-A-PHASE AND TEL-O-PHASE
2) Ralph - Ipmat
R - Replicate - Interphase
a - appear - Prophase
l - line up - Metaphase
p - pull apart - Anaphase
h - half and hide - Telophase & Cytokinesis

3) I'm Pretty Mean And Tough

4) Interphase, prophase, metaphase, anaphase, telophase, cytokinesis= I pray monthly at the church

5) Metaphase = chromosomes in the Middle
Anaphase = Apart

6) IPMAT- I Pee on the MAT

7) IPMAT - I punched MAT
(suggested by a student named MATT!)

8) IPMAT = I Poop More After Tacos

9) I Passed My Algebra Test

UNIT III – Genetics

1) PHenotype is what you'd see in a PHoto (when I start the unit, we're usually looking first at visible traits like rolling the tongue, skin color, etc, then get more complicated)

2) You can remember that your "phenotype" is your"physical appearance" because both start with "F".

FOR DNA

1) When writing the letters C and G both curved, so they match up
When writing the letters A and T only straight lines are used, so they match up

2) Cytosine, Uracil and Thymine are all PYrimidines, because you CUT a pie.
Pyrimidines are a single ring, just like a pie is drawn as a single circle
If you can remember CUT and pyrimidine, then the others (Adenine and Guanine) are purines and a double ring

2) GUANINE AND ADENINE ARE PURINES "GREEN APPLES ARE PURE"
thymine and cytosine PYRIMIDINES "TORTILLA CHIPS ARE SHAPED LIKE PYRAMIDS" (ALSO HAVE Y IN THEIR NAME LIKE PYRIMIDINE

3) how many rings does a purine have – 2 RINGS - think guanine and adenine have 2 "N" in their name

4) how many H bonds between C and G – 3 H-BONDS - think C is the third letter of alphabet

5) C - G = chips always goes with guacamole
A - T = at Taco Bell

6) If your kids know the show "24", Jack Bauer works for the CTU (Counter Terrorist Organization) or (cytosine, thymine, uracil). They protect the pyramids (pyrimidines)

7) Pure As Gold (The purines are Adenine and guanine).

FOR TRANSCRIPTION

1) Adenine matches with Uracil, when changing to RNA because, as I tell my students, DNA (adenine) is the boss and gets to tell mRNA to go out to the cytoplasm and deliver the messages..."Hey you, go deliver this to the ribosome" = "A U, go deliver this to the ribosome" (very New Yawk!)

2) What does the cell do with InTrons? puts them In the Trash

3) INtrons are "IN the way" and need to be removed
EXons are Expressed

4) INtrons are IN between the genes

FOR TRANSLATION

1) For ribosomes, the three sites are A (arrive) P (park) E (exit)

UNIT IV – Mechanisms of Evolution

FOR THE NAMES AND SEQUENCE OF THE GEOLOGICAL EONS AND PERIODS:
1) Happily Arguing, Pregnant Camels Often Sit Down Carefully.
Perhaps Their Joints Creak.
Possible Early Oiling Might Perhaps Prevent Rusting.

Hadean Archaean Proterozoic Cambrian Ordovician Silurian
Devonian Carboniferous
Permian Triassic Jurassic Cretaceous
Paleocene Eocene Oligocene Miocene Pliocene Pleistocene Recent

2) Can Olivia See Down My Pants Pocket?
The Janitor Can!
Try, Quickly!

Cambrian Ordovician Silurian Devonian Mississippian
Pennsylvanian Permian
Triassic Jurassic Cretaceous
Tertiary Quaternary

UNIT V – The evolutionary History of Biological Diversity

UNIT VI – Plant Form and Function

FOR XYLEM AND PHLOEM:

1)xy goes up high, phlo goes down low

2) Phloem. The ph sound like food, transports "food" not water

3) To remember Xylem and Phloem, we remember that xylem carries water, and that "X" and "W" are next to each other in the alphabet, and that Phloem carries Food (sounds phonetically the same)

4) You xyl'em on up,
and you phlo'em on down!
(repeat as you march/dance)

5) water "zips up the xylem" and food "flows down the phloem".

UNIT VII – Animal Form and Function

FOR HORMONES:

1) To remember the hormones of the anterior pituitary, we sing them to the "ABC" song:
ACTH, LH, FSH, GH, TSH, PROLACTIN.....and MSH (sang like "and many more" in the Happy birthday song)

2) Calcitonin versus Parathyroid hormone:
Calcitonin = deposits calcium IN the bones (students usually
associate calcium with bones, not blood)
PTH - Perhaps Trash the Hip (weakened bones = damaged hip)

3) When Na+ asks the axon if it is okay to enter (during the resting state), the cell says No Admittance.
When K+ asks the axon the same question, the cell says (o)K!

FOR CLASSIFICATION:

1) Properly Cleaned Cafeteria Plates Need Normal Routine Maintenance After All Eating Concludes
(Porifera, Cnidaria, Ctenophora, Platyhelminthes, Nemertea, Nematoda, Rotifera, Mollusca, Annelida, Arthropoda, Echinodermata, Chordata)-

FOR HUMAN SYSTEMS:

1) SLIC MEN R RED
Skeletal
Lymphatic
Integumentary
Circulatory
Muscular
Endocrine
Nervous
Respiratory
Reproductive
Excretory
Digestive

2) Every class tries eagerly to learn many stories. Clearly, no story actually ends purely and peacefully.
Ectoderm epidermis of skin, tooth enamel, lining of mouth, Sensory receptors in epidermis, cornea, lens of eye, nervous system, adrenal medulla, epithelial of pineal and pituitary glands.

3)Mothers naturally supply many meals of steak and iceberg lettuce, especially satisfying carrot and lentil soup, really special supper dishes like boiled cod and cabbage.
Mesoderm: Notocord, skeletal and muscular systems, Muscles of stomach and intestine layers, excretory system, circulatory and lymphatic systems, reproductive systems, skin’s dermis, lining of body cavities, and adrenal cortex.

FOR VERTEBRAE

1)7 - 12- 5
7 cervical, 12 thoracic, 5 lumbar
and then of course, it's 1 sacrum, 1 coccyx

2) For the regions of the back, we always did:
Cyanide
Tastes
Like
Sweet
Candy

3) Valves of the heart:
Try (Tricuspid)
Pulling (Pulmonary)
My (Mitral)
Aorta (Aortic)

UNIT IX – Ecology

LABS AND MISC

1) I decide the Independent variable
you collect Data for the Dependent variable

2) SI: Kangaroos Hop Down Mountains Drinking Chocolate Milk

OR: King Henry Died Because (basic) drinking chocolate milk [Mondays (micro)]

FEEL FREE TO ADD

Ch 41: Animal Nutrition Continued....

2009-03-16T19:35:00.002-06:00

The small intestine is the longest (6m) section of the alimentary canal.

The beginning of the small intestine is the site of most of the hydrolysis of macromolecules, and the rest of the small intestine is responsible for the absorption of nutrients into the blood.

The first section of the small intestine is known as the duodenum.

In the duodenum, the acid chyme mixes with secretions from the pancreas (bicarbonate, which acts as a buffer against acid chyme), the liver (bile, which contains bile salts-detergents that aid in digestion and help stabilize fat emulsions), the gall bladder, and the intestinal wall itself.

* Gall Bladder has no digestive secretions.

Here is how particular macromolecules are broken down in the small intestine:

1. Carbohydrates- The breakdown of starch and glycogen begins with salivary amylase in the mouth. In the small intestine, pancreatic amylases break starch, glycogen, and small polysaccharides into disaccharides.

The breakdown of these disaccharides occurs at the wall of the intestinal epithelium, and then the monosaccharides are quickly absorbed (they directly enter the blood)

2. Proteins- Pepsin begins the breakdown of proteins in the stomach and in the small intestine, trypsin and chymotrypsin break polypeptides into smaller chains. Dipeptidases, carboxypeptidase, and aminopeptidase break apart into amino acids. Considered the last source of energy.

3. Nucleic Acids- The breakdown of nucleic acids is similar to that of proteins. In the small intestine, nucleases break then down into nucleotides, nitrogenous bases, sugars, and phosphate groups.

4. Fats- Digestion of fats starts in the small intestine. Bile salts coat the fat droplets and keep then from coalescing (in emulsification), and lipase hydrolyzes them. Most absorbed fat first enters the lymphatic system.

Most absorbtion of nutrients occurs in the small intestine, and the epithelial lining of the small intestine has folds called villi, which in turn bear projections called microvilli-both of which radically increase the surface area available for absorption.

In each villus is a set of tiny blood vessels called capillaries and a lymph vessel called a lacteal.

Monosaccharides, such as glucose, cross via passive diffusion, whereas amino acids and dipeptides are pumped across in active transport.

The lacteal will absorb small fatty acids.

The capillaries and veins that drain the nutrients away from the villi all join the hepatic portal vessel, which brings them to the liver. The liver metabolizes the organic molecules in various ways.

Some hormones involved in digestion are gastrin, which stimulates the secretion of gastric juice; and enterogastrones, such as secretin and cholescystolcinin (CCK), that are secreted by the walls of the duodenum and that prompts the digestion of various macromolecules.

Multiple Choice:

1. How long is the small intestine?

a. 15 m

b. 8 m

c. 6 m

d. 4 m

2. In the duodenum, the acid chyme mixes with secretion from what?

a. Gall Bladder

b. Pancreas

c. Stomach

d. Liver

3. The breakdown of starch and glycogen begins with what in the mouth?

a. pacreatic amylase

b. pepsin

c. salivary amylase

d. carboxpeptidase

4. Where does the digestion of fats start?

a. stomach

b. small intestine

c. large intestine

d. esophagus

5. All of these hormones are involved in digestion, except:

a. Gastrin

b. Trypsin

c. Secretin

d. Cholescystokinin

Answers: 1. C 2. B 3. C 4. B 5. B

Chapter 41 - Animal Nutrition

2009-03-10T17:26:00.002-06:00

** Note: the text in blue is the notes given in class, and the text in black is given from the website 'course-notes'. Some of the pictures also forward you to videos relating to the surrounding material.**

Overview: The Need to Feed

All animals eat other organisms—dead or alive, whole or by the piece (including parasites).

· In general, animals fit into one of three dietary categories.

1. Herbivores, such as gorillas, cows, hares, and many snails, eat mainly autotrophs (plants and algae).

2. Carnivores, such as sharks, hawks, spiders, and snakes, eat other animals.

3. Omnivores, such as cockroaches, bears, raccoons, and humans, consume animal and plant or algal matter.

o Humans evolved as hunters, scavengers, and gatherers.

· While the terms herbivore, carnivore, and omnivore represent the kinds of food that an animal usually eats, most animals are opportunistic, eating foods that are outside their main dietary category when these foods are available.

o For example, cattle and deer, which are herbivores, may occasionally eat small animals or bird eggs.

o Most carnivores obtain some nutrients from plant materials that remain in the digestive tract of the prey that they eat.

o All animals consume bacteria along with other types of food.

For any animal, a nutritionally adequate diet must satisfy three nutritional needs:

A balanced diet must provide fuel for cellular work.
It must supply the organic raw materials needed to construct organic molecules.
Essential nutrients that the animal cannot make from raw materials must be provided in its food.

Concept 41.1 Homeostatic mechanisms manage an animal’s energy budget

· The flow of food energy into and out of an animal can be viewed as a “budget,” with the production of ATP accounting for the largest fraction by far of the energy budget of most animals.

o ATP powers basal or resting metabolism, as well as activity and, in endothermic animals, thermoregulation.

· Nearly all ATP generation is based on the oxidation of organic fuel molecules—carbohydrates, proteins, and fats—in cellular respiration.

o The monomers of any of these substances can be used as fuel.

o Fats are especially rich in energy, liberating about twice the energy liberated from an equal amount of carbohydrate or protein during oxidation.

· When an animal takes in more calories than it needs to produce ATP, the excess can be used for biosynthesis.

o This biosynthesis can be used to grow in size or for reproduction, or it can be stored in energy depots.

o In humans, the liver and muscle cells store energy as glycogen, a polymer made up of many glucose units.

Concept 41.2 An animal’s diet must supply carbon skeletons and essential nutrients

In addition to fuel for ATP production, an animal’s diet must supply all the raw materials for biosynthesis (the formation of a chemical compound by a living organism).

o Given a source of organic carbon (such as sugar) and a source of organic nitrogen (usually in amino acids from the digestion of proteins), animals can fabricate a great variety of organic molecules—carbohydrates, proteins, and lipids.

An animal whose diet is missing one or more essential nutrients is said to be malnourished.

Animal nutrition: Nutritional Requirements

An adequate diet supplies three things: fuel in the form of chemical energy, the organics raw materials for biosynthesis, and essential nutrients.

The essential nutrients required by an animal are those that must be obtained in pre-assembled organic for because the animal cannot produce them.

About half of the 20 essential amino acids must be obtained from food. There are also essential fatty acids which animals can not make and must ingest. Nonessential can be made form other substances in the body.

Absorbed nutrients are in the form of monomers.

Vitamins are organic molecules that are required in the diet in small amounts. They are used as co-factors in enzyme-controlled biochemical reactions.

**Minerals, such as calcium and phosphorus, are simple inorganic nutrients that are also required in the diet in small amounts**

· There are four classes of essential nutrients: essential amino acids, essential fatty acids, vitamins, and minerals.

· Animals require 20 amino acids to make proteins.

o Most animals can synthesize half of these if their diet includes organic nitrogen.

· Because the body cannot easily store amino acids, a diet with all essential amino acids must be eaten each day, or protein synthesis is retarded.

· Some animals have special adaptations that get them through periods where their bodies demand extraordinary amounts of protein.

o For example, penguins use muscle proteins as a source of amino acids to make new proteins during molting.

While animals can synthesize most of the fatty acids they need, they cannot synthesize essential fatty acids.

These are certain unsaturated fatty acids, including linoleic acids, which are required by humans.
Most diets furnish ample quantities of essential fatty acids, and thus deficiencies are rare.

Vitamins are organic molecules required in the diet in quantities that are quite small compared with the relatively large quantities of essential amino acids and fatty acids animals need.

While vitamins are required in tiny amounts—from about 0.01 mg to 100 mg per day—depending on the vitamin, vitamin deficiency (or overdose in some cases) can cause serious problems.

So far, 13 vitamins essential to humans have been identified.

These can be grouped into water-soluble vitamins and fat-soluble vitamins, with extremely diverse physiological functions.

The water-soluble vitamins include the B complex, which consists of several compounds that function as coenzymes in key metabolic processes.

Vitamin C, also water soluble, is required for the production of connective tissue.
Excessive amounts of water-soluble vitamins are excreted in urine, and moderate overdoses are probably harmless.

The fat-soluble vitamins are A, D, E, and K.

They have a wide variety of functions.
Vitamin A is incorporated in the visual pigments of the eye.
Vitamin D aids in calcium absorption and bone formation.
Vitamin E seems to protect membrane phospholipids from oxidation.
Vitamin K is required for blood clotting.
Excess amounts of fat-soluble vitamins are not excreted but are deposited in body fat.

Overconsumption may lead to toxic accumulations of these compounds.

Minerals are simple inorganic nutrients, usually required in small amounts—from less than 1 mg to about 2,500 mg per day.

Mineral requirements vary with animal species.
Humans and other vertebrates require relatively large quantities of calcium and phosphorus for the construction and maintenance of bone.

Calcium is also necessary for the normal functioning of nerves and muscles.
Phosphorus is a component of the cytochromes that function in cellular respiration.

Sodium, potassium, and chloride are important in nerve function and have a major influence on the osmotic balance between cells and the interstitial fluids.

Concept 41.3 The main stages of food processing are ingestion, digestion, absorption, and elimination

Overview: Food Processing

1. Ingestion is the act of taking in food, and it is the first stage in the processing of food. Ingestion, the act of eating, is only the first stage of food processing.

· Food is “packaged” in bulk form and contains very complex arrays of molecules, including large polymers and various substances that may be difficult to process or even toxic.

2. Animals cannot use macromolecules like proteins, fats, and carbohydrates in the form of starch or other polysaccharides.

· First, polymers are too large to pass through membranes and enter the cells of the animal.

· Second, the macromolecules that make up an animal are not identical to those of its food.

i. In building their macromolecules, however, all organisms use common monomers.

ii. For example, soybeans, fruit flies, and humans all assemble their proteins from the same 20 amino acids.

3. Digestion is the second stage of the processing of food. It is the breakdown of food into small molecules capable of being absorbed by the cells of the body.

Digestion cleaves fats into glycerol and fatty acids, catalyzed by enzymes, cleaves nucleic acids into nucleotides, polysaccharides into simple sugars.
Digestion, the second stage of food processing, is the process of breaking food down into molecules small enough for the body to absorb.

Digestion cleaves macromolecules into their component monomers, which the animal then uses to make its own molecules or as fuel for ATP production.
Polysaccharides and disaccharides are split into simple sugars.
Fats are digested to glycerol and fatty acids.
Proteins are broken down into amino acids.
Nucleic acids are cleaved into nucleotides.

Digestion reverses the process that a cell uses to link together monomers to form macromolecules.

Rather than removing a molecule of water for each new covalent bond formed, digestion breaks bonds with the addition of water via enzymatic hydrolysis.
A variety of hydrolytic enzymes catalyze the digestion of each of the classes of macromolecules found in food.

4. Enzymatic hydrolysis is the reaction by which macromolecules are broken up. It involves the addition of water. It obviously includes enzymes.

· Chemical digestion is usually preceded by mechanical fragmentation of the food—by chewing, for instance.

i. Breaking food into smaller pieces increases the surface area exposed to digestive juices containing hydrolytic enzymes.

5. Absorption is the stage in food processing when the body’s cells take up small molecules from the digestive tract. Cross the cell membrane with transport mechanisms.

· After the food is digested, the animal’s cells take up small molecules such as amino acids and simple sugars from the digestive compartment, a process called absorption.

6. Elimination occurs when the undigested material passes out of the digestive tract.

· During elimination, undigested material passes out of the digestive compartment.

7. Intracellular digestion occurs within a cell enclosed by a protective membrane. Sponges digest their food this way.

8. Extracellular digestion is carried out by most animals; in this type of digestion, food is broken down outside of cells.

· Many simple animals have a gastrovascular cavity, where digestion takes place. These simple animals have a single opening through which food enters and waste is eliminated.

More complex animals have complete digestive tracts (alimentary canals) which are one-way digestive tubes that begin with the mouth at one end of the terminate in the anus at the other.

Concept 41.4 Each organ of the mammalian digestive system has specialized food-processing functions

· The general principles of food processing are similar for a diversity of animals, including the mammalian system that we will use as a representative example.

· The mammalian digestive system consists of the alimentary canal and various accessory glands that secrete digestive juices into the canal through ducts.

o Peristalsis, rhythmic waves of contraction by smooth muscles in the walls of the canal, pushes food along.

o Sphincters, muscular ring-like valves, regulate the passage of material between specialized chambers of the canal.

o The accessory glands include the salivary glands, the pancreas, the liver, and the gallbladder.

· After chewing and swallowing, it takes 5 to 10 seconds for food to pass down the esophagus to the stomach, where it spends 2 to 6 hours being partially digested.

· Final digestion and nutrient absorption occur in the small intestine over a period of 5 to 6 hours.

· In 12 to 24 hours, any undigested material passes through the large intestine, and feces are expelled through the anus.

The oral cavity, pharynx, and esophagus initiate food processing.

Digestion occurs in specialized compartments.

To avoid digesting their own cells and tissues, most organisms conduct digestion in specialized compartments.

· The simplest digestive compartments are food vacuoles, organelles in which hydrolytic enzymes break down food without digesting the cell’s own cytoplasm, a process termed intracellular digestion.

· This process begins after a cell has engulfed food by phagocytosis or pinocytosis.

· Newly formed food vacuoles fuse with lysosomes, which are organelles containing hydrolytic enzymes.

· These tubes are called complete digestive tracts or alimentary canals.

o Because food moves in one direction, the tube can be organized into specialized regions that carry out digestion and nutrient absorption in a stepwise fashion.

o In addition, animals with alimentary canals can eat more food before the earlier meal is completely digested.

Step by Step of the Human Digestive System

When food is in the mouth, or oral cavity, a nervous reflex occur which causes saliva to be secreted into the mouth. Saliva lubricates the food and contains the enzyme salivary amylase, which hydrolyzes starch and glycogen into smaller polysaccharides and the disaccharide maltose. This is typically the first type of macromolecules to be enzymatically attacked.

**Know what type of digestion (chemical, etc.) is occurring. Know also where the polysaccharide/monosaccharide is being digested and what is happening**

During chewing, food is shaped into a ball called a bolus. After being swallowed, the bolus enters the pharynx – a junction that opens to the esophagus and the trachea. During swallowing, the epiglottis (a flap made of cartilage) moves to the cover the trachea. This will divert the food to go down the esophagus (also called the alimentary canal).

The esophagus moves food from the pharynx down to the stomach through peristalsis – rhythmic waves of contraction by smooth muscle in the walls of the esophagus (also called the alimentary canal).

The stomach is in the upper abdominal cavity, and its functions include storing food and secreting gastric juice. Gastric juice contains hydrochloric acid, which is very acidic (pH of about 2). Gastric juice breaks down the extra cellular matrix of meat and plant materials, and it also kills most of the bacteria ingested with the food.

Gastrin is a hormone produced by the epithelial lining of the stomach.

Pepsin is an enzyme in gastric juice that begins to hydrolyze proteins into smaller polypeptides. Pepsin is secreted in an inactive form called pepsinogen, which is activated by the hydrochloric acid in the stomach.

The result of digestion in the stomach is a substance called acid chyme. The acid chime is shunted from the end of the stomach into the beginning of the small intestine via the pyloric sphincter.

____________________________________________________________________________________

Review Questions:

1. Which of the following organs is incorrectly paired with its function?

a. stomach - protein digestion

b. oral cavity - starch digestion

c. large intestine - bile production

d. small intestine - nutrient absorption

e. pancreas - enzyme production

2. The esophagus conducts food from the pharynx down to the stomach by

a. peristalsis

b. gastrin

c. sphincters

3. Chemical digestion is usually preceded by __________ fragmentation of the food—by chewing, for instance.

a. organic

b. mechanical

c. reflexive

____________________________________________________________________________________

Answers:

1. c 2. a 3. b

'Course-Notes' Website

2009-03-05T17:35:00.004-07:00

Hi everyone, I have found a website called "Course Notes" that provides a comprehensive chapter summary for every chapter in the Campbell's Biology 7th edition book. (So the only downside to this is that the girls who have the 8th edition book will have a couple of chapters that are slightly different.)
This website is great for supplementing your class notes and study guides as it offers more than our notes in class. The URL for this website is: http://www.course-notes.org/ . To get to the biology chapter reviews click on the 'Science' tab, then 'biology' and then if you scroll to the bottom both chapter 'overviews' and 'slides' similar to the ones in class are offered.
I hope this helps any who need it!

Chapter 40

2009-03-05T10:27:00.002-07:00

An introduction to animal structure and function: Functional Anatomy: An Overview

-Anatomy is defined as the study of the structures of an organism.
-Physiology is defined as the study of the functions of an organism.
-Tissues are groups of cells that have a common structure and function.

-There are 4 types of tissue:

Epithelial tissue occurs in the sheets of tightly packed cells, covers the body, lines the organs of the body, and acts as a protective barrier. One side of an epithelial cell is always bound to an underling supportive surface called the basement membrane. The outside surface is facing either air or a fluid environment.
Connective tissue mainly supports and binds to other tissues. It consists of scattered cells within an extracellular matrix. Some connective tissues are cartilage, tendons, ligaments, bone, and blood.
Muscle tissue is composed of long cells called muscle fibers. Muscle fibers contract when they are stimulated by a nerve impulse. This is the most abundant tissue in most animals. There are three types of muscle- skeletal muscle, cardiac muscle, and smooth muscle. *Know types of muscles!*
The functional unit of nervous tissue is the nerve cell, or neuron. The tissue senses and transmits signals from one part of the body to other neurons, glands, muscles, and the brain.

-Organs are organized groups of tissues.

-Organ systems are organs that work together cooperatively to do a common function.
-For animal survival tissues, organs, and organ systems must act in a coordinated manner. Two major organ systems specialize in control and coordination.
-In the endocrine system, chemical signals called hormones are released into the bloodstream and are broadcast throughout the body. Different hormones cause specific effects, but only in cells with specific receptors for that released hormone.

-Endocrine cells secrete specific hormones signaling molecules (shown as red dots)- into the bloodstream. Only cells expressing the corresponding receptor receive and respond to the signal.

-In the nervous system, neurons transmit information between specific locations. Only three types of cells receive nerve impulses: neurons, muscle cells, and endocrine cells. Ex: hand on the stove.
-Nerve cells (neurons) generate signals that travel along axons. only cells that for a specialized junction with the axon of an activated neuron receive and respond to the signal. *Way to remember axons: away. they carry the neurons away.*

Regulating the internal Environment
-The interstitial fluid refers to the internal environment of an animal. Homeostasis is the state of internal balance on an animal. The internal environment is maintained to be constant even when the external environment changes.
-Homeostasis control systems have three components- a receptor, a control, and an effector. The receptor detects a change; the control center processes information an directs the effector to make an appropriate response.

*QUESTIONS:

Where are collagenous fibers primarily found in animal cells?

a) connective
b) straited
c) bone
2. Is blood a tissue?
a) yes
b) no
3. Which of the three muscle types is voluntary?
a) cardiac muscle
b) skeletal muscle
c) smooth muscle

*Answers:
1. a
2. a
3. b

Animal Behavior

2009-03-05T08:11:00.002-07:00

Besides using the Marine Tank to study animal behavior, another interesting study would be with poison dart frogs. Poison dart frogs lose the venom/toxin when removed from their natural habitat. They get their venom from eating a certain ant and then secrete the venom from their skin.

Poison dart frogs also have coloration, natural selection, defense mechanisms, etc.

Here is a web link on the frogs

http://www.frognet.org/gallery/

Mrs. Lyon

Chapter 40 Vocab and packet review!

2009-03-04T13:48:00.005-07:00

Hey girls! Remember chapter 40 vocab is due tomorrow, and so are test corrections!

Chapter 40 Vocab
Epithelial tissue: Sheets of tightly packed cells that line organs and body cavities as well as external services.

Columnar: Refers to the shape of epithelial cells that are taller than they are wide

Squamous: An epithelium characterized by its most superficial layer consisting of flat, scale-like cells called squamous cell
Collagenous fibers: Glycoprotein fibers found extensively in connective tissue and bone

Fibroblast: A type of cell in loose connective tissue that secretes the protein ingredients into threads that form the fabric of the clot.

Macrophages: A phagocytic cell present in many tissues that function in innate immunity by destroying microbes and in acquired immunity an antigen-presenting cell.

Interstitial fluid: An internal environment of vertebrates, consisting of the fluid filling the spaces between cells.

Positive feedback: A physiological control mechanism in which a change in a variable triggers mechanisms that amplify the change.

Tendon: A fibrous connective tissue that attaches muscle to bone.

Negative feedback: A primary mechanism of homeostasis, whereby a change in a physiological variable triggers a response that counteracts the initial fluctuation.

Abdominal cavity: The abdominal cavity is the body cavity of the human body (and animal bodies) that holds the bulk of the viscera and which is located below (or inferior to) the thoracic cavity, and above the pelvic cavity. It is a part of the abdominopelvic cavity.

Homeostasis: The steady-state physiological condition of the body.

Neuron: A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane.

Ligament: A fibrous connective tissue that joins bones together at joints.

Osteoblasts: Cells that arises from fibroblasts and are associated with the production of bone.

Nervous tissue: Tissue made up of neurons and supportive cells.

Skeletal muscle: Muscle that is generally responsible for the voluntary movements of the body; also called striated muscle.

Smooth muscle: A type of muscle lacking the striations of skeletal and cardiac muscle because of the uniform distribution of myosin filaments in the cell; responsible for involuntary body activities.

In class today we went over the packet, here are some of the harder questions explained:

5. Which of the following pairs are the best examples of homologous structures
ANSWER: B. Bat wing and human hand

These both are mammal and share similar DNA. Therefore, have evolved a more recent common ancestor.

19. What probably explains the inclusion of rabbits on this research?
ANSWER: D. Mutations to homologous genes

The species that is least related to others is the outgroup. In this situation the rabbit is at least 3.2 percent away from the other mammals, making it the outgroup.

30. If the experimental population of E. coli lacks an F factor ot F plasmid, and if bacteriophage are excluded form the bacterial cultures, then which of these is a means by which beneficial mutations might be transmitted horizontally to other E. Coli cells?
ANSWER: C. via transformation

If the E. coli lacks and F factor or F plasmid then it can't be via conjugation. Then if it can't be via conjugation then it can't be via sex pili. Since bacteriaphage are excluded from the bacterial cultures, then it can't be via transduction. So the only remaining answer is via transformation.

34. Which of the following traits do archaeans and bacteria share?
ANSWER: B. 2 and 3

Basically, because bacteria have peptidoglycan in the cell wall and archaens do not, the composition of the cell wall is different, so 1 can't be it, mak ing a and e incorrect. And both bacteria and archaea have a plasma membrane, so 2 is correct and c is therefore incorrect (doesn't include 2) then, both lack a nuclear envelope so 3 is correct, and the only b includes both 2 and 3 so that must be the correct answer. And 4 just doesn't make sense so it can't be d either

36. Jams, jellies, preserves, honey and other foodstuffs with a high sugar content hardly ever become contaminated by bacteria, even whent he food containers are left open at room temperature. This is because bacteria that encounter such an environment.
ANSWER: B. undergo death by plasmolysis

Because the foodstuffs have such a high sugar concentration, the water from the bacteria would leave the bacteria cell and goes into the jam because it's hypotonic and so the cell undergoes plasmolysis and dies.

Done by Megan Timlin with contribution from Abbey Dunn

Ch 27

2009-03-03T20:43:00.005-07:00

Hi Ladies!

I hope everyone is having a great evening, 2 more days of school until the weekend! :)

Don't forget that test corrections are due on THURSDAY and ch 26 & 27 take home is due TOMORROW. Here are today's notes:

Chapter 27: Prokaryotes

Section 27.1: Structural, functional, and genetic adaptions contribute to prokaryotic success

Almost all prokaryotic cells have a cell wall. This wall helps maintain their shape, provides protection, and prevents the cell from bursting in a hypotonic environment.

Cell Surface Structures

The most common shapes are rods, spheres, and helices. Most are approx. 1-5 micrometers in length. This is perhaps 1/10 the size of a typical eukaryotic cell. Most cell walls of bacteria contain peptidoglycan (modified sugar polymers linked by short peptides). To distinguish the different types of bacteria, scientists use a process called gram staining. In this process, the bacteria are stained through a series of steps including the addition of crystal violet, an alcohol, and a mordant. The result is that the gram-positive bacteria are darker purple and the gram-negative bacteria are lighter. gram-positive bacteria have simpler cell walls so they contain more peptidoglycan which alludes to a darker purple color. The gram-negative bacteria have a more complicated cell wall so they contain less peptiglycan and are lighter in color.

The Cell wall of many prokaryotes also is covered by a capsule (a sticky layer of protein or polysaccharide). This capsule allows the cell to adhere to other individuals or their substrate. Other cells stick to their substrate or one another by appendages called fimbriae and pili. (Fimbriae are more numerous and shorter than pili).

Motility

Prokaryotic cells are able to move because of flagella. Many of these prokaryotes exhibit taxis or the movement away from or towards a stimulus like nutrients or oxygen. An example of these prokaryotes is E. Coli which exhibits taxis toward other individuals of its species leading to the formation of colonies.

Internal and Genomic Organization

Prokaryotes do not have a true nuclei nor do they have internal-compartmentalization. Prokaryotes' single chromosome is located in a nucleoid region. In addition to having one chromosome, a prokaryote may also contain rings of DNA called plasmids. These plasmids provide resistance against atibiotics and direct the metabolism of rare nutrients.

Reproduction and Adaption

Prokaryotic cells do not reproduce sexually. Instead they reproduce asexually through binary fission. Although meiosis and fertililzation does not occur in prokaryotes, genetic diveristy occurs through three different processes: transformation, transduction, and conjugation.

transduction: viral phages carry bacterial genes from one host cell to another

transformation: the alteration of a bacteria's cells genotype by the uptake of foreign DNA from the surrounding environment

conjugation: the direct transfer of genetic material between two bacterial phages that are temporarily joined

These organisms are able to adapt to their environments quickly and reproduce often so populations are constantly growing and evolving. Some prokaryotes have the ability to live in harsh conditions such as very salty water and in extreme temperatures. Certain bacteria can even form resistant cells called endospores (a thick-coated, resistant cell produced within a bacterial cell exposed to harsh conditions.

Section 27.2: A great diversity of nutritional and metabolic adaptions have evolved in prokaryotes

All organisms can be categorized by how they obtain energy and carbon used in building molecules that make up cells. Prokaryotes can be placed into four groups:

1. photoautotrophs- photosynthetic organisms that use light energy to produce their food and synthesize organic compounds from CO2. Examples include plants and algae.

2. chemoautotrophs- oxidize inorganic substances such as hydrogen sulfide, ammonia, and ferrous ions for energy. They also need CO2 as a carbon source.

3. photoheterotrophs-use light for energy but obtain their carbon in organic form. Examples include many marine prokaryotes.

4. chemoheterotrophs- consume organic molecules for both energy and carbon. Most commonly found among prokaryotes as well as protists, fungi, and even some plants

Metabolic Relationships to Oxygen

obligate aerobes- use 02 for cell respiration and can't grow without it

facultative anaerobes- use 02 if present but Can also grow by fermentation

obligate anaerobes- poisoned by 02, live only by fermentation

anaerobic respiration- the process in which chemical energy is extracted from substances other than 02 like nitrate ions or sulfate ions. They also accept electrons at the end of electron transport chains.

Question:

Match the term with the right definition

1) obligate aerobes a. live only by fermentation and are poisoned by O2

2) obligate anaerobes b. viral phages carry bacterial genes from one host cell to another

3) transformation c. oxidize inorganic substances such as hydrogen sulfide for energy

4) facilitative anaerobes d. use o2 for cell respiration

5) chemoautotrophs e. use light energy to make food and synthesize organic molecules from CO2

6) conjugation f. the direct transfer of genetic material between bacterial phages temp. joined

7) transduction g. the alteration of a cell's genotype by the uptake of foreign DNA

ANSWERS: 1. D 2. A 3. G 4. C 5. F 6.B