Sunday, October 19, 2008

Chapter 5: Section I & II Review

Hi girls, as you know we have a quiz over the first two sections of Chapter 5. Here is a short review to help you study. :) If you need extra help memorizing/understanding concepts look for a blue section-- ignore these analogies if they just confuse you even more.

Section One 

5.1 Macromules are polymers, built from monomers.

A polymer is made of covalently bonded monomers
-monomers are connected through condensation reactions, specifically a dehydration reaction because water molecules are lost as the monomers connect 

-hydrolysis is the exact opposite process of  the dehydration reaction. it tears down polymers by adding water and breaking the covalent bonds between the monomers
-a hydrogen from the water attaches to one monomer and a hydroxyl group attaches to the monomer next to it (used in digestion)

Use this familiar scenario to help you study: Jack and Jill are at a SMA dance. They are dancing with each other (as a polymer). Ms. Mac (the enzyme) insists they leave room for Jesus (water). So Jack and Jill (a polymer) separate (becoming monomers) because Jesus (the H2O molecule) comes between them (dehydration reaction). When Ms. Mac turns around, the 'Jesus space' (water) falls away allowing Jack and Jill (separate monomers) to once again dance together (as a polymer) (hydrolysis reaction).

5.2 Carbohydrates serve as fuel and building material.

-monosaccharides (*consist of 4-7 carbons) fuel cellular work and act as raw material for the creation of other types of small organic molecules
-a carbohydrate is given away by its 2:1 ratio of hydrogen to oxygen!
-two join together by glycosidic linkage to form disaccharides (*consist of 8-14 carbons)
-100s to 1000s of monosaccharides also joined together by glycosidic linkage form polysaccharides
-store materials such as sugar and provide building material for structures protecting the cell or whole organism (ex: cellulose, chitin, glycogen) 

If we think of 'saccharides' as people, then you are a monosaccharide. When you and your best friend are together, you guys are a disaccharide. Finally, when you hang out with your whole group of friends, all of you together are a polysaccharide.

Section Two

5.3 Lipids are a diverse group of hydrophobic molecules.

-lipids are not polymers...however, they are hydrophobic like the other biological membrane groups 
-ex: fats, steroids
-glycerol backbone + two fatty acid tails = phospholipid 
-glycerol molecule + three fatty acids = FAT (aka triglyceride)
-joined by ester linkage resulting in triacylglycerol
-fatty acids vary by length, number, and location or double bonds
-fatty acids: saturated? unsaturated? WHAT?
-saturated fatty acid contains no double bonds
-unsaturated fatty acid contains at least one double bond causing a kink in the hydrocarbon chain

If you need help remembering the difference, maybe try this: Fatty acids are like strands of hair. When your hair is perfectly smooth it is saturated. Now think of most days when you look in the mirror and you see one annoying strand out of place... your hair is unsaturated. *But remember, unlike your bed-head, an unsaturated fatty acid is actually a good thing. The kinks (or loose hairs) prevent the molecules from packing tightly and keep them from solidifying at room temperature.

5.4 Proteins have many structures, resulting in a wide range of functions.

-proteins make of 50% of the cell
-they speed up chemical reactions, offer structural support, storage, transport, cellular communication, movement, and defense again foreign substances (ex: enzymes)
-there are 20 amino acids that make up protein molecules 
-carboxyl group + amino group + variable group (R) = AMINO ACID

Try this analogy: Nick and Conor are twins. They have identical DNA (carboxyl group and amino group). However, their personalities are very different (R group). Just like Nick and Conor, each amino acid is built from the same two things, the carboxyl group and amino group. However, the amino acids' variable groups give them their unique identity and properties.

If you have been looking at all those key terms in pink and panicking because you have no idea what they mean, never fear... a vocabulary quiz is here!

Match the term with it's definition. Answers are at the bottom.

1. fat
2. disaccharides
3. triacylglycerol
4. saturated fatty acid
5. unsaturated fatty acid
6. proteins
7. amino acids
8. ester linkage
9. lipids
10. polymer
11. polysaccharides
12. monomer
13. condensation reaction
14. dehydration reaction
15. hydrolysis
16. monosaccharides
17. glycosidic linkage

a) long molecules consisting of many similar or identical building blocks linked by covalent bonds
b) repeating units that serve as building blocks of a polymer
c) reaction in which two molecules are covalently bonded to each other through loss of a smaller molecule
d) condensation reaction where water molecule is lost
e) process reversing dehydration reaction
f) simplest sugar 
g) a covalent bond formed between two monosaccharides by a dehydration reaction
h) two monosaccharides joined by glycosidic linkage
i) macromules; polymers with a few hundred to a few thousand monosaccharides joined byglycosidic linkages
j) one of a group of compounds, including fats, phospholipids, and steroids, that mix poorly, if at all, with water
k) a lipid that is formed from a glycerol molecule and three fatty acids
l) a bond between a hydroxyl group and a carboxyl group
m) a fat formed by three fatty acids linked to a glycerol molecule
n) hydrocarbon chain with no double bonds between the carbon atoms
o) hydrocarbon chain with at least one double bond resulting by the removal of hydrogen atoms from the carbon skeleton
p) consists of one or more polypeptides, each folded and coiled into a specific three-dimensional structure
q) organic molecules possessing both carboxyl and amino groups

Answers: (1.k) (2.h) (3.m) (4.n) (5.o) (6.p) (7.q) (8.l) (9.j) (10.a) (11.i) (12.b) (13.c) (14.d) (15.e) (16.f) (17.g) 


1 comment:

Lindsey said...

sorry the quiz is in such awkward formatting i can't make it work in columns..