CHE 4310 Fall 2011
Biochemistry Review 1I
A general note: Short answer questions are just that, short. Writing a paragraph filled with every term
you can remember from class won’t improve your answer— just answer clearly, succinctly, and in your
own words.
Useful information: R = 8.315 J/mol*K
T = 298 K
1. Discuss the entropy changes inside an egg during the development of a chick.
2. In your own words, explain the difference between ∆G'° and ∆G.
3. The reaction A + B → C has a ΔG'° of +13 kJ/mol. What is the Keq' for this reaction, and
does it favor products or reactants? Show your work.
4. The standard free-energy changes for the reactions below are given.
Glucose 1-phosphate → glucose 6-phosphate
ΔG'° = –7.1 kJ/mol
Glucose 6-phosphate → fructose 6-phosphate
ΔG'° = +1.7 kJ/mol
What is the ΔG'° for the overall reaction?
5. Draw an example structure that is a good electrophile, and put a star beside the
electrophilic atom. Draw an example structure that is a good nucleophile, and put a # beside
the nucleophilic atom.
6. The standard reduction potentials (E'°) for the following half reactions are given.
Fumarate + 2H+ + 2e– → succinate E'° = +0.031 V
FAD + 2H+ + 2e– → FADH2
E'° = –0.219 V
(The Faraday constant, , is 96.48 kJ/V·mol.)
What is the ΔG'° for the overall reaction? Show your work.
7. Draw the amino acid Alanine:
8.
1
2
3
4
5
____________________________________________________
Asp-Glu
Gly-Arg
Trp-Tyr
His-Glu
Leu-Val
Which one of the above dipeptides (1 through 4):
(a) Is most negatively charged at pH 7?
(b) Contains the largest number of nonpolar R groups?
9. Glycine has two dissociable protons: one with a pKa of 2.3, the other with a pKa of 9.6.
Draw the structure of Glycine and indicate where these protons are attached.
10. Under what pH range or ranges would glycine have good buffering power?
11. When proteins are purified by gel electrophoresis, SDS (sodium dodecyl sulfate) is often
included with the protein. What is the purpose of this SDS, and what does it enable
biochemists to investigate?
12. During a protein purification in lab, you find that the specific activity of your protein did not
increase after running it through a specific purification procedure. What does this imply about
the procedure you performed?
13. In your own words, what is the primary structure of a protein?
14. Describe the general shape that  strands form. What forces hold the strands in this form?
15. Name two amino acid residues you would not expect to commonly be found in an α helix:
16. What type of amino acid residue is typically found in the interior of a water-soluble
globular protein? Why?
17. Explain why a denatured protein might not refold in vitro.