Chapter 5 Review Assessment

Reviewing Concepts Multiple Choice: Choose the letter of the best answer.

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

a. cellulose

b. sucrose

c. water

d. testosterone

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

a. polysaccharide

b. carbohydrate

c. monosaccharide

d. glycogen

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

a. hydrocarbon

b. hydrophobic

c. hydrophilic

d. organic

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

a. protein

b. lipid

c. amino acid

d. carbohydrate

5. The 20 amino acids vary only in their answer: c. amino groups

a. carboxyl groups.

b. side groups.

c. amino groups.

d. lipid groups.

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

a. catalyst.

b. sucrose.

c. active site.

d. substrate.

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

a. adds heat to a reaction, speeding it up

b. lowers the activation energy of a reaction

c. cools a reaction, slowing it down

d. raises 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?

Not enough having carbons in body or proteins and fats that you need for each day.

9. How are glucose, sucrose, and starch related?

They are all in polysaccharides and they have different functions.

10. What are steroids? Describe two functions they have in cells.

Steroids are lipid molecule with four fused carbon rings. They work at both male's and female's sex hormone, and testosterone.

11. How are polypeptides related to proteins?

Because each links in the proteins are made out of several polypeptides formed together.

12. How does denaturation affect the ability of a protein to function?

Denaturation unfavorable changes in temperature, pH, or some other quality of the enviornment can cause a protein to unravel and lose its normal shape.

Applying Concepts Analyzing Information

14. Analyzing Diagrams The reaction below shows two amino acids joining together.

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

b. What is this kind of reaction called? Explain.

c. If an amino acid were added to this chain, at what two places could it attach?

15. Analyzing Graphs Use the graph to answer the questions below.

a. At which temperature does enzyme A perform best? Enzyme B?

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.

c. Propose a hypothesis that explains why the rate of the reaction catalyzed by enzyme A slows down at temperatures above 40°C.