Exam 2 CH 203

May 25, 1995

There are three pages and thirteen questions on this exam. Be sure you have them all.

1. Describe or define precisely

Spontaneous process

Vitamin

ATP

2. What is meant by the primary, secondary, and tertiary structure of a protein? Provide an example for each.

3. Draw three (3) esters with the formula C₆H₁₂O₂. Give the IUPAC name of ONE of them.

4. The isoelectric point of serine (G = -CH₂OH) is 5.7. Draw the predominant form of the molecule in water of pH 3.0, in pH 5.7, and in pH 8.0.

5. A.) What three types of molecules provide food for people?

B.) Describe the type of reaction responsible for the breakdown of each of the food types listed above as the food is initially digested. Indicate the type of compound which results.

C.) Which of the food types would a person recovering from surgery require in the greatest amount and why?

6. Describe at least two ways in which an enzyme might speed up a biochemical reaction.

7. Does the presence of an enzyme alter the sign or magnitude of the G of a reaction? Justify your answer briefly.

8. What is the difference between digestion and metabolism?

9. Discuss the difference between plants and animals as far as glucose is involved.

10. Household soap is a mixture of sodium and potassium salts of the fatty acids resulting from the hydrolysis of animal fat.

A.) Describe the nature of the hydrolysis reaction, beginning with the animal fat shown, and identify the products by circling them.

B.) Why would such soap molecules be useful for "cleaning"?

11. Insulin is a globular protein. Why must diabetic patients receive insulin subcutaneously by injection rather than orally?

12. What general type of reaction do carboxylic acids and their derivatives commonly undergo? Give three examples of such reactions to illustrate your point.

13. Draw the actual molecular structure (not an abbreviation) of two dipeptides that are isomers. For each molecule, circle the "side group" and indicate the peptide link.