Answer 25 of the 26 questions among questions 1 to 26 (each 2 points)
Questions 27-31 (each 10 points), bonus question (2 points).
Question 1 . What is the common strategy by which catalysis occurs?
A) increasing the probability of product formation
B) shifting the reaction equilibrium
C) stabilization of transition state
D) all of the above
E) none of the above
Question 2 . The Gibbs free energy of activation is
A) the difference between the substrate and the transition state.
B) the difference between the substrate and the product.
C) the difference between the product and the transition state.
D) all of the above.
E) none of the above.
Question 3 . In this type of inhibition the enzyme can form a complex with either the substrate (ES) or the inhibitor (EI), but not both.
A) Competitive
B) Non-competitive
C) Mixed
D) All of the above
E) None of the above
Question 4. Which amino acids in chymotrypsin are found in the active site and are participants in substrate cleavage?
A) his, ser, asp B) his, ser C) asp, lys D) lys, arg E) his, ser, arg
Question 5. The metal most commonly found at the active site of metalloproteases is
A) zinc. B) calcium. C) selenium. D) magnesium. E) sodium.
Question 6. Nucleotide monophosphate kinases function to
A) transfer the phosphate from NTP to NDP.
B) transfer the phosphate from NTP to NMP.
C) transfer the phosphate from NMP to NDP.
D) phosphorylate NADH.
E) transfer the phosphate from NTP to water.
Question 7. Allosteric proteins
A) contain distinct regulatory sites and have multiple functioning sites.
B) display cooperativity.
C) always consist of several identical subunits.

D) a and b.
E) all of the above.
Question 8. What is the Bohr effect?
A) the ability of hemoglobin to retain oxygen when in competition with myoglobin
B) the regulation of hemoglobin binding by hydrogen ions and carbon dioxide
C) the alteration of hemoglobin conformation during low oxygen stress
D) all of the above
E) none of the above
Question 9. How is trypsin activity turned off?
A) by dephosphorylation D) all of the above
B) by an inhibitor protein E) none of the above
C) by a second cleavage
Question 10. An aldehyde and alcohol can react to form a
A) hemiaketal.
B) hemiketal.
D) all of the above.
E) none of the above.
C) hemiacetal.
Question 11. Furanose rings are in a(n) ____ conformation.
A) chair B) envelope C) boat D) all of the above E) none of the above
Question 12. Which of the following membranes would be the most fluid?
A) a bilayer made of lipids with polyunsaturated 18 carbon-fatty acids
B) a bilayer made of lipids with saturated 18 carbon-fatty acids
C) a bilayer made of lipids with saturated 16 carbon-fatty acids
D) a bilayer made of lipids with polyunsaturated 16 carbon-fatty acids
E) All of the above are equivalent in fluidity.
Question 13. Name three amino acids that are positively charged at a neutral pH.
A) lys, arg, and his D) lys, arg, and pro
B) his, arg, and cys E) arg, glu, and his
C) cys, arg, and met
Question 14.
The coding strand has the _____________ sequence as the RNA transcript
(except T instead of U).
A) same B) complementary C) reverse D) palindromic E) none of the above
Question 15. The rate of RNA synthesis in E. Coli is approximately ___________ nucleotides per minute.
A) 15 B) 50 C) 100 D) 1000 E) none of the above
Question 16. RNA Polymerase I transcribes the genes for
A) mRNA precursors. D) all of the above.

B) 18S, 5.8 S, and 28S rRNA.
C) most tRNA.
E) none of the above.
Question 17. Given are five Km values for the binding of substrates to a particular enzyme. Which has the strongest affinity when k − 1 is greater than k2?
A) 150 mM B) 0.15 mM C) 150
μ
M D) 1.5 nM E) 15000 pM
Question 18. Which of the following is not true?
A) Enzymes force reactions to proceed in only one direction.
B) Enzymes alter the equilibrium of the reaction.
C) Enzymes alter the standard free energy of the reaction.
D) All of the above are true.
Question 19. Binding of a water molecule to the zinc ion induces
A) a hydronium ion to form.
B) a large conformation change in the binding site.
C) ionization of a his residue, which functions as a strong nucleophile.
D) a lowered pK for water, which leads to formation of a zinc bound hydroxide ion.
E) an altered Km value.
Question 20. If you carried out site-directed mutagenesis of subtilisin, changing serine
221 to isoleucine, what would you expect?
A) a large change in Km D) a and c
B) a small change in Km E) b and c
C) a large change in Kcat
Question 21. The relaxed form of an allosteric enzyme has _________ affinity for the substrates.
A) higher B) equal C) lower D) no E) none of the above
Question 22. Why is the peptide bond planar?
A) Bulky side chains prevent free rotation around the bond.
B) It contains partial double bond character, preventing rotation.
C) Hydrogen bonding between the NH and C=O groups limits movement.
D) None of the above.
E) All of the above.
Question 23. Amino acids to which sugars are commonly linked.
A) tyrosine and asparagine D) serine and threonine
B) serine, threonine, and asparagine E) a and d
C) serine, tyrosine, and asparagines

Question 24. Carbohydrates are
A) aldehydes with multiple hydroxyl groups.
B) ketones with multiple hydroxyl groups.
C) acids with multiple hydroxyl groups.
D) a and b.
E) none of the above.
Question 25. The most common motif found in membrane spanning proteins is
A)
α
helices of nonpolar amino acids that pass through the membrane.
B)
α
helices of charged amino acids that form channels via extensive hydrogen bonding.
C) triple helix of
α
helices.
D) a helix-turn-helix arrangement of the peptide strands.
E) none of the above.
Question 26. The low incidence of protein or lipid flip-flop in a membrane preserves
A) membrane fluidity. D) all of the above.
B) membrane melting temperatures. E) none of the above.
C) membrane asymmetry.
Question 27. Fill in the blanks.
a) Mirror images of each other are called ____________. b) Sugars that vary at a single asymmetric carbon are called __________. c) Substituents on the ring carbon atoms in chair conformations can be
equitorial or ____________. d) The storage form of glucose in animals____________.. e) Enzymes that do not have the required cofactor bound are called f) A tightly bound cofactor might be called a ___________. g) Kcat is often referred to as the _________________. h) Proteases function by what common mechanism? ____________. i) _A technique that permits rapid monitoring of enzyme kinetics. ____________. j) The metal ion frequently found at active sites containing phosphate
groups. ____________.

Question 28. What are the two systems for naming the positions of the double bonds?
Provide examples.
Question 29.
What caused a “burst” of activity followed by a steady state reaction when chymotrypsin was studied by stop-flow techniques?
Question 30. Draw and label a typical phospholipid.
Question 31. Describe the significant differences between eukaryotic and prokaryotic

transcription and translation.
Bonus question:
Which individual won a Nobel Prize for his landmark work in sequencing the protein insulin?
A) Pauling B) McClintock C) Gilbert D) Maxam E) Sanger