Tuesday, December 2, 2008

Chapter 9 Vocab! + Lab

Hey! Today we had a big test today, hope everyone did well! Don't forget Chapter 9 vocabulary quiz is tomorrow and the Mitosis Lab is due Friday!

Redox reaction: A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another; short for oxidation-reduction reaction.
➢ Another term for an oxidation-reduction reaction. A redox reaction is any reaction in which electrons are removed from one molecule or atom and transferred to another molecule or atom. In such a reaction one substance is oxidized (loses electrons) while the other is reduced (gains electrons).

Oxidation: The loss of electrons from a substance involved in a redox reaction.
➢ A chemical reaction that removes electrons from an atom or molecule.

Proton motive force: The potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across biological membranes during chemiosmosis.
➢ Proton electrochemical gradient established by energy-transducing membranes.

Reducing agent: The electron donor in a redox reaction.
➢ A compound that causes reduction, thereby itself becoming oxidized

ATP synthase: A complex of several membrane proteins that provide a port through which proteins diffuse. This complex functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. ATP synthases are found in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotes.
➢ An enzyme that catalyzes the conversion of phosphate and ADP into ATP during oxidative phosphorylation in mitochondria and bacteria or photophosphorylation in chloroplasts.
Substrate-level phosphorylation: The formation of ATP by an enzyme directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.
➢ A type of chemical reaction that results in the formation of adenosine triphosphate (ATP) by the direct transfer of a phosphate group to adenosine diphosphate (ADP) from a reactive intermediate.

NAD+: Nicotinamide adenine dinucleotide, a coenzyme that can accept an electron and acts as an electron carrier in the electron transport chain.
➢ Electron carrier called nicotinamide adenine dinudeotid

Oxidative phosphorylation: The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major state of cellular respiration.
➢ Synthesis of ATP through various reactions whereby energy for the cell is obtained.

Reduction: The addition of electrons to a substance involved in a redox reaction.
➢ Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed.

Chemiosmosis: An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Most ATP synthesis in cells occurs by chemiosmosis.
➢ The mechanism through which ATP is produced in the inner membrane of the mitochondrion. The electron transport system transfers protons from the inner compartment to the outer and as the protons flow back to the inner compartment, the energy of their movement is used to add phosphate to ADP, forming ATP.

Oxidizing agent: The electron acceptor in a redox reaction.
➢ A substance that accepts/gains electrons and undergoes reduction. It "allows" the other substance to undergo oxidation

Electron transport chain: A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
➢ A group of electron carriers in mitochondria that transport electrons to and from each other in a sequence, in order to generate ATP.

Cytochromes: An iron-containing protein that is a compound of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells.
➢ Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.

Aero- air
Chemi- chemical

Mitosis and Meiosis Lab Mini Quiz

1) In which phase do the centromere regions of each pair of chromosomes separate?
a. Metphase
b. Telophase
c. Anaphase

2) In which phase do the chromatin threads thicken?
a. Anaphase
b. Interphase
c. Prometaphase

3) In which phase to the chromosomes condense then a new nuclear envelope forms around each group of chromosomes?
a. Prophase
b. Telophase
c. Metaphase

4) In which phase have the chromosome pairs moved to the center of the spindle?
a. Anaphase
b. Telophase
c. Metaphase

5) How many daughter cells does the completion of meiosis form?
a. 4
b. 2
c. 8

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

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