Final Exam

CH 130

June 1998

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.

Soap molecule

Zwitterion

Tertiary amine

Enzyme

Cracking of hydrocarbons

Geometrical isomers

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

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

Using any specific tripeptide of your choice, show two structural isomers for your tripeptide. (Actual structures, not abbreviations)

5. a. What is meant by primary, secondary, and tertiary amines? Use drawings to illustrate your point.

Can all three types of amines react with carboxylic acids to form amides? Show the basic (unassisted) reaction for amide formation and explain your point.

6. 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.

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

your point by drawing the amino acid threonine, with

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

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

8. The molecule triptophan is shown to the right.

a. What is the general class of molecule that triptophan represents?

Identify the functional groups on the

molecule, and if applicable, indicate if

a functional group is primary, secondary,

or tertiary.

b. This molecule is rather more soluble in either acidic or basic water than in pure water. Why is this expected? Draw the expected forms for each of the three cases.

9. We have studied a number of different types of polymerization reactions this term. Show how three (3) different types of polymers could be formed by the reaction between reactants that you choose.

10. Draw the structure for cis-2-pentene.

11. Summarize briefly the main idea behind the experiment "The Clean Machine." A typical fat is shown below.

12. a. What is meant by a "hydrogen bond?"

Give three distinctly different examples in which the formation of hydrogen bonds is critical to the chemical process involved.

13. Write the reaction products that result when specific primary and secondary alcohols are mildly oxidized, giving the chemical (IUPAC) name of each reactant and each product. You can choose any specific alcohols.

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

15. a. In what way does free rotation play a role in the formation of protein secondary structures such as -helix and random coil?

b. If a protein were to change from one secondary structure to another, would it be forming a different isomer or a different conformer? Explain your reasoning.

16. Draw the structures of all the di-chlorinated isomers resulting when Cl₂ reacts with C₃H₈ (2 Cl per molecule). Give the IUPAC names.

17. Draw the structures of the two molecules ethylbutanoate and 3-pentanone.

18. a. In what ways are the proteins in mammals and bacteria similar and in what ways are the proteins different? Your answer should discuss the basic chemical compositions.

Along the same lines, in what way would the DNA of mammals and bacteria be similar and in what way would they be different?