· web viewwhen oxygen is binding to myoglobin, we see a _____ curve which tells us that when the...

Biochemistry Mock Exam 2 Perry Griffin

1. When oxygen is binding to myoglobin, we see a _____ curve which tells us that when the concentration of oxygen is much less than P50, _____ O2 _____ MbO2.

a. Sigmoidal; increasing; increases

b. Hyperbolic; decreasing; decreases

c. Sigmoidal; decreasing; decreases

d. Hyperbolic; increasing; increases e. Both A and B

2. The P50 value of O2 binding to Hb is _____ than that of Mb meaning that oxygen tends to bind to _____ better.

a. Less than; Mbb. More than; Hbc. Equal to; Mbd. Equal to; Hbe. None (more than; Mb)

3. The cooperative model of oxygen binding exhibited in _____ demonstrates its ability to _____ bind the initial oxygen while _____ binding the last oxygen.

a. Hb; weakly; tightlyb. Mb; weakly; tightlyc. Hb; tightly; weaklyd. Mb; tightly; weaklye. Hb; weakly; weakly

4. In the Bohr shift, the Hb binding curve shifts _____ as the pH decreases from 7.6 to 7.2.

a. Leftb. Rightc. Upd. Downe. North by Northwest

5. ATP is composed of ____ phosphoanhydride bond(s) and ____ phosphoester bond(s). There is/are also ____ mixed anhydride bonds that give ATP its energy-payload.


a. 1;2;1b. 3;0;2c. 0;3;1d. 2;1;2e. none of the above(2;1;0)

6. The standard free energy change for pyrophosphate hydrolysis to 2Pi is ____ (kJ/mol).

a. -20 to -30b. -30 to -40c. -20 to -30d. -30 to -40e. none

7. The standard free energy change Glycerol-3-Pi to Glycerol+Pi is ____ (kJ/mol).a. 0 to -10b. -10 to -20c. -20 to -30d. -30 to -40e. -50 to -60

8. ATP has a maximum negative charge of ____ while PPPi has a negative charge of ____.

a. -3; -4b. -5; -4c. -4; -5d. -4; -3e. none

9. The hydrolysis of free energy of phosphoenolpyruvate is about ____ kJ/mol (closest answer).

a. 0 to -10b. -10 to -20c. -20 to -30d. -30 to -40e. -50 to -60

10. The previous question has the free energy that it does due to the ____ bond present in PEP.

a. Phosphoester b. Phosphoanhydridec. Mixed anhydrided. Phosphodiestere. None

11. Rank the concentration of the adenine nucleotides for their presence in a cell and at equilibrium, respectively.


a. [ADP]>[ATP]>[AMP]; [ADP]>[AMP]>[ATP]b. [AMP]>[ADP]>[ATP]; [ATP]>[ADP]>[AMP]c. [ATP]>[AMP]>[ADP]; [ATP]>[ADP]>[AMP]d. [ATP]>[ADP]>[AMP]; [AMP]>[ADP]>[ATP]e. none

12. At equilibrium, the reactants in the reaction AMP + Pi ADP + H2O and ADP + Pi ATP + H2O are ____ times more abundant than the products. This means that in the reaction AMP + 2Pi ATP + H2O, AMP is ____ times more abundant than ATP.

a. 108; 106

b. 1012;106

c. 106; 1012

d. 106; 108

e. None

13. In the enzyme-mediated reaction of S P, there is an increase in the velocity of the reaction though there is a(an) ____ in GΔ o that results in a(an) ____ in the formation of S from P.

a. Decrease; increaseb. Increase; decreasec. No change; increase --enzyme increase velocity both ways and do not

affect thermodynamic constants d. No change; decreasee. None

14. When all other condition are the same, the activation energy of an enzyme mediated reaction will always be ____ than that of an unmediated reaction.

a. Higher b. Lowerc. Depends on the enzyme classd. Depends on the temperature e. Depends on the pH and the temperature

15. ____ is the enzyme class that catalyzes the removal of water by the formation of a double bond.

a. Oxidoreductase b. Ligasec. Lyased. Hydrolasee. None

16. ____ is the enzyme class that can move a group from one molecule to another. ____ is an example of an enzyme from this group that can ____ a phosphate group onto another molecule from ATP.

a. Oxidoreductase; kinase; add


b. Lyase; phosphatase; removec. Lyase; kinase; removed. Transferase; kinase; adde. Transferase; kinase; remove

17. The conversion of acetaldehyde to ethanol is mediated by a(an) ____ enzyme (class) using the ____ cosubtrate. This reaction ____ spontaneous.

a. Oxidoreductase; NADH; is notb. Oxidoreductase; NAD+; is c. Transferase; NADH; isd. Transferase; NAD+; is note. None

18. In the conversion of D-glyceraldehyde to dihydroxyacetone, the ____ enzyme class is used.

a. Transferaseb. Isomerasec. Lyased. Hydrolasee. None

19. The oxidation number of the carbon atom in –CO2- is ____ while it is ____ in the -

CHOH- group. a. 0; 0b. +4; +2c. +3; 0d. 0; +3e. +2; +4

20. The change in oxidation number of the carbon in an aldehyde functional group and the carbon in a carboxylate functional group is ____.

a. -1b. 0c. 1d. 2e. 3

21. The ____ step of the mechanism of a Michaelis-Menten (MM) enzyme is the slowest step. As a result, ____ happens here and ____ is formed.


a. Second; binding; S+Eb. First; binding; EPc. Second; chemistry; S+Ed. Third; release; ESe. Second; chemistry; EP

22. The reaction velocity for X+YZ quadruples when either [X] is doubled or [Y] is quadrupled. This reaction is ____ order for X and ____ order for Y and ____-order overall.

a. 2;4;4b. 4;2;6c. 1;2;3d. 2;1;3e. None

23. When [S]>> Km for a MM enzyme, the rxn velocity is ____ order for [S] and it approaches ____. When [S]<<Km for a MM enzyme, the rxn velocity is ____ order for [S] and tend to ____ linearly

a. 1st; Vmax/Km; 0th ; increaseb. 0th; Km/Vmax; 1st; decreasec. 1st; Vmax; 0th; decreased. 0th; Vmax; 1st; increasee. none

24. For a MM enzyme, catalytic perfection is achieved when ____ approaches 108 (M-1S-1).a. Km

b. 1/Vmax

c. kcat/Km

d. Vmax/Km

e. Either A or C

25. Competitive inhibitors of a MM enzyme bind to ____ and have ____ Vmax’s. Noncompetitive inhibitors, however, will ____ Vmax.

a. E; lower; higherb. ES; higher; lowerc. E; non-changing; lowerd. E; non-changing; highere. ES; non-changing; lower

26. When the kinetic data of a MM enzyme is plotted as a double reciprocal plot, it is called a Lineweaver-Burk plot. These plots transform ____ data to ____ data. The Y-intercepts of these graphs are ____.

a. Hyperbolic; linear; -1/Km


b. Sigmoidal; linear; 1/Vmax

c. Hyperbolic; linear; 1/Vmax

d. Linear; hyperbolic; -1/Km

e. Either B or C depending on the situation

27. Allosteric enzymes exhibit ____ velocity curves where activation implies a shift to the ____ and inhibition implies a shift to the ____.

a. Linear; right; leftb. Hyperbolic; left; rightc. Sigmoidal; right; leftd. Sigmoidal; left; righte. Hyperbolic; right; left

28. The most significant metabolic flux in the forward direction of AP occurs when Q/Keq

is ____. For the reverse reaction of the above process, the ratio of Keq/Q of ____ provides the most flux.

a. 10-6;10-4

b. 10-12;10-6

c. 10-2;10-4

d. 10-4;10-2

e. Either B or D

29. Given that GΔ o = RT QK eq

, the most forward

reaction with the greatest driving force would have which of the following ratios for Q/Keq?

a. 108

b. 1012

c. 10-8

d. 10-12

e. Either B or D

30. Which of the following GΔ ’ values has the greatest tendency to achieve equilibrium? a. -20b. -40c. 5d. 40e. Both B and D

31. During vigorous muscle contraction, ____ stores the chemical energy necessary to rapidly regenerate ATP.

a. Creatineb. Creatine-Pi


c. PEPd. ADPe. Either A or B

32. In cells, ATP is ____ times more prevalent than AMP. a. 5b. 106

c. 1/5 d. 10-6

e. 50

33. In the net reaction of glycolysis, there are ____ pyruvate produced and ____ ATP produced.

a. 1;1b. 2;2c. 1;2d. 2;1e. 1;0

34. In glycolysis, fructose-6-phosphate is converted to F-1,6-BP using a ____ enzyme (class), specifically a ____.

a. Ligase; phosphataseb. Transferase; kinasec. Ligase; kinased. Transferase; phosphatasee. None

35. In glycolysis, each glycerate-1,3-bisphosphate is converted to pyruvate and ____ ATP using ____ rxn steps.

a. 1;3b. 1;4c. 2;3d. 2;4e. None

36. In glycolysis, which reaction(s) consume(s) or produce(s) ATP and contribute to metabolic flux?

a. 3b. 1 and 3c. 7 and 10d. 1,3, and 7e. 1, 3, and 10


37. Reaction 10 of glycolysis converts ____ to pyruvate. It utilizes a ____ bond and ____ spontaneous.

a. 2-phospohoglycerate; phosphoester; isb. PEP; phosphoester; is ----- this one was “mixed anhydride” but that is

incorrect...PEP has no mixed anhydride bondsc. 2-phospohoglycerate; phosphoester; is notd. PEP; phosphoanhydride; is note. PEP; phosphoanhydride; is

38. The net metabolic flux generated for the reaction of glucose 2pyruvate is approximately ____ kJ/mol. This net reaction ____ spontaneous

a. -50; isb. -60; isc. -70; isd. 70; is note. 60; is not

39. Reaction ____ of glycolysis is the only reaction to utilize a dehydrogenase enzyme. It converts ____ to 1,3-BPG. This reaction ____ near equilibrium.

a. 1; glyceraldehyde-3-phosphate; is

b. 6; glyceraldehyde-3-phosphate; is not

c. 3; glyceraldehyde-3-phosphate; is

d. 1; 3-phosphoglycerate; is note. 6; glyceraldehyde-3-phosphate; is

40. Glycogen branches using _____ glycosidic bonds that result in more _____ ends; these brances occur ~ every _____ residues.

a. (1α 4); reducing; 2b. (1α 6); non-reducing; 4c. (1α 4);non-reducing; 4d. (1α 6); reducing; 2e. none

41. Glycogen biosynthesis _____ to metabolic flux while it’s degradation _____.

a. Does not contribute; doesb. Contributes; does notc. Contributes; contributesd. Does not contribute; does note. None


42. In the net reaction of glycogen degradation, glycogen phosphorylase produces _____ while phosphoglucomutase produces _____.

a. Glucose-1-P; Glucose-1,6-BPb. Glucose-1-P; Glucose-6-Pc. Glucose-1,6-BP; Glucose-6-Pd. A and Be. B and C

43. In the intestine, glycosidases, which are _____ , break down starches into their _____ substrates that can be absorbed by the intestinal mucosa.

a. Phsophorylases; disaccharideb. hydrolases; disaccharidec. Phsophorylases; monosaccharided. hydrolases; monosaccharidee. none

44. In a well-fed metabolic state, serum _____ is taken up by all cells.

a. Glucose-6-Pb. Glucosec. Glucose-1-Pd. UDP-glucosee. None

45. The conversion of Glucose to UDP-Glucose cleaves _____ phosphoanhydride bonds and makes _____ phosphoanhydride bonds.

a. 1; 2b. 0; 2c. 2; 1d. 2; 0e. none

46. When blood glucose levels are high, _____ is released into the blood and glycogen synthase is _____.

a. Insulin; is phosphorylatedb. Insulin; is dephosphorylatedc. Glucagon; is phosphorylatedd. Glucagon; is dephosphorylatede. None


**The last question was not covered by Muccio in lecture, so don’t focus on it unless you are interested in these particular mechanisms and pathways.**

· web viewwhen oxygen is binding to myoglobin, we see a _____ curve which tells us that when the...

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