Final Exam CH 130

June 1997

There are 18 questions and 4 pages to this exam. Each is worth 5 points, except numbers 1 and 2 which are worth 10 points each.

1. Define precisely five (5) of the following six.

Unsaturated hydrocarbon

 Essential amino acid

 Vitamin

 Complementary base pair

 Gene

 Structural isomers

2. Describe how information contained in DNA is used to guide the synthesis of a specific protein.

3. Define both genetic information and genetic code, and make it clear what the difference is between them, if any.

4. What is meant by the primary, secondary, and tertiary structures of proteins? Use drawings if it helps you illustrate your point.

5. List four distinctly different ways in which living systems make use of proteins. You do not need to name or otherwise identify any specific protein.

6. a. What is required for a carbon to be chiral? Illustrate

your point by drawing the amino acid, isoleucine, with

G = -CH(CH₃)CH₂CH₃ , circling any chiral carbon(s).

 b. Under what conditions would optical isomers react differently from each other?

7. a. The drug quinine is shown to the right.

Identify the functional groups on the

molecule, and if applicable, indicate if

a functional group is primary, secondary,

or tertiary.

b. This drug is not particularly soluble in the form shown. What is a common way that such molecules can be made water soluble? Describe the reaction.

8. Using any specific dipeptide of your choice,

c. Show how free rotation leads to different conformers

d. Show at least two structural isomers for your dipeptide (including the original)

9. Show how either a polyester or a polyamide can be formed by the reaction between two reactants that you choose.

10. Draw the structure for trans-2-hexene.

11. Summarize briefly the main ideas behind the two experiments listed:

a. The vitamin C experiment -- "60 mg a Day"

b. "The Clean Machine"

12. It is said that a mutation in RNA is less serious than a mutation in DNA. Why is this so?

13. Write the reaction products that result when primary, secondary, and tertiary alcohols are oxidized, giving the family name of each type of product.

14. Describe the way in which nucleic acids and proteins have analogous structural features.

15. a. What is a hydrogen bond? Under what conditions does it form?

b. Compare it in strength to typical dispersive forces between molecules and to covalent bonds.

c. Describe in words or with diagrams two specific ways in which the hydrogen bond plays a major role in biochemistry.

16. There are more than 50,000 different enzymes in the human body. What do enzymes do? Why can't just a few enzymes do the job?

17. Draw the structures of the two molecules propylbutanoate and 2-ethylpentanoic acid.

18. What are some of the similarities and differences between higher forms of life, such as mammals, and lower forms (such as plants and bacteria) as far as chemistry is concerned? Your answer should discuss the basic chemical compositions.