Self Quiz Answers

1. Which of the following compounds would be most likely to be hydrophilic?

a. a terpene
*b. levulose
c. cholesterol
d. a triglyceride

2. Give two distinct functions of carbohydrates in plants.

Carbohydrates are used for structure, for energy, for energy storage, and for synthesis into other necessary biochemicals. (Any two)

3. Identify the carbohydrates among the following compounds:

a. CH₂OH \| H₂N - C - COOH \| H	c. O OH \\ \| C - C - CH₂OH / \| HO H
*b. O OH \\ \| C - C - CH₂OH / \| H H	*d. H OH H \| \| \| HO - C - C - C - C - OH \| \| \|\| \| H H O H

4. For each of the carbohydrates in #3 state whether they are reducing or nonreducing sugars.

Both b and d are reducing sugars, although d would require conversion to an aldehyde under basic conditions.

5. Draw the complete a-D-glucose molecule. Circle (or mark) the number 4 carbon atom.

These are two possible answers. Answers that show hydrogen atoms or the carbon atoms that are left out of these diagrams are also correct (even better). The #4C is at the left corner of the ring.

Structure of alpha-D-glucose. [67046a.jpg]

6. Sucrose is a disaccharide formed by a(n) ________ reaction from________.

a. hydrolysis.....two glucose molecules
b. dehydration....two fructose molecules
c. addition.......a molecule of fructose and one of glucose
d. hydrolysis.....two fructose molecules
*e. dehydration....a molecule of glucose and one of fructose

7. Indicate whether each of the following terms or descriptions applies to photosynthesis, respiration, both or neither.

a. The overall process is oxidation-reduction. - Both (Photosynthesis is reduction, respiration is oxidation.)
b. Transfers energy from bonds in glucose to bonds in ATP. - Respiration
c. Produces diatomic oxygen molecules. - Photosynthesis
d. Produces carbon dioxide. - Respiration
e. Takes place in both plants and animals. - Respiration

8. What feature of cellulose makes it undigestible for most animals?

a. the linkages are 1,4
*b. the linkages are b
c. there are too many side chains
d. the side chains are linked 1,6 to the main chain

9. Which of these is not part of the process by which aerobic organisms extract energy from carbohydrates?

a. the TCA cycle
b. the electron transport chain
*c. conversion of ATP to ADP - (This comes later, after it has been extracted from carbohydrates and put into ATP.)
d. conversion of pyruvate and CoA to acetyl CoA

10. Explain why equal amounts (by weight) of fats and carbohydrates do not supply an organism with equal amounts of energy.

An equal weight of fat contains less oxygen (and thus a higher percentage of carbon and hydrogen) and will go through addition steps of oxidation resulting in the release of more energy.

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