Chapter 5 Review

p.106-107 #1-12,14-15

Multiple Choice
1. Which of the following is not an organic molecule?
a) water

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

3. Which term is 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 exzyme acts upon is called the
d) substrate

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

Short Answer
8. Besides satisfying your hunger, why else might you consume a big bowl of pasta the night before a race?
I wold consume a big bowl of pasta the night before a race to make sure I would have enough energy stored in my body so I can do better on the race.

9. How are glucose, sucrose, and starch related?
Glucose is a monosaccharide that bonds with a fructose to form a sucrose. Starch is a polysaccharide that consists entirely of glucose.

10. What are steroids? Describe two functions they have in cells.
Steroids are a type of lipid molecules where the carbon skeleton forms four fused rings. Some steroids circulate the body as chemical signals. It can also surround a cell, acting like a membrane.

11. How are polypeptides related to proteins?
Polypeptides are long chains of amino acids linked together to form a protein.

12. How does denaturation affect the ability of a protein to function?
Denaturation causes a protein to unravel and lose its normal shape. Since a protein's shape determines its functions and when it loses it shape, the protein can not function

14. Analyzing Diagrams
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 reaction is called dehydration reaction. De- means removing, and hydro- means water. So basically, water is being removed from the amino acids to bond them.

c) If an amino acid were added to this chain, at what two places could it attach?
If an amino acid were added this this chain, it would be on the OH on the right or another attached to a H on the left side.

15. Analyzing Graphs
a) At which temperature does enzyme A perform best? Enzyme B?
Enzyme A performs best at around 37 degrees C and enzyme B performs best around 78 degrees C.

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 a thermophilic bacteria and Enzyme B is a type of enzyme 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 C.
The rate of the reaction catalyzed by enzyme A slows down at temperates above 40 degrees C because the reaction ended.