Chapter 5 Review

page 106-107 #1-12, 14,15

1. Which of the following is not an organic molecule?
c) water

2. Which of the following terms includes all the other terms on this list?
b)carbohydrate

3. Which term is the most appropriate to describe a molecule that dissolves easily in water?
c) hydrophilic

4. Cholesterol is an example of what kind of molecule?
b) lipid

5. The 20 amino acids vary only in their
b) side groups

6. A specific reactant an enzyme acts upon is called the
d) substrate

7. An enzyme does which of the following?
b) lowers the activation energy of a reaction

8. Besides satisfying your hunger, why else might you consume a big bowl of pasta the night before a race?
Besides satisfying your hunger, you may also consume a big bowl of pasta because your body wants energy for the next day.

9) How are glucose, sucrose, and starch related?Glucose and starch are both chains of many glucose monomers. Glucose, sucrose, and starch are all sugars.

10) What are steroids? Describe two functions they have in cells.
Steroids are lipid molecules in which the carbon skeleton forms four fused rings.

1. They circulate in your body as chemical signs.

2. The steroids in males and females causes the major differences in appearance between male and female mammals.

11)How are polypeptides related to proteins?
Polypeptides are cells that create proteins by linking amino acids together into a chain.

12)How does denaturation affect the ability of a protein to function?
Denaturation can cause a protein to unravel and lose its normal shape.

14)

a. One product of this reaction is represented by a question mark. Which molecule is it?
water

b. What is this kind of reaction called? Explain.
This kind of reaction is called a dehydration reaction. It is when water is removed from amino acids to bond them.

c. If an amino acid were added to this chain, at what two places could it attach?
The OH on the right side of the reaction or the H on the other part of the reaction.

15)
a) At which temperature does enzyme A perform best? Enzyme B?
Enzyme A performs best at 37 degrees celsius and Enzyme B performs best at around 78 degrees celsius.
b)Knowing that one of these enzymes is found in humans and the other in thermophilic (heat-loving) bacteria, hypothesize which enzyme came from which organism.
Enzyme A is thermophilic and Enzyme B is found in humans.
c)Propose a hypothesis that explains why the rate of the reaction catalyzed by enzyme A slows down at temperatures above 40 degrees celsius.
The reaction slowed down and ended and that was why the reaction catalyzed by enzyme A slows down at temperature above 40 degrees celsius.