The reaction A + B → C has a ∆G0’ of -20 kJ/mol at 25 0C. Starting under

Standard Conditions, one can predict that:

A. at equilibrium, the concentration of B will exceed the concentration of A.

B. at equilibrium, the concentration of C will be less than the concentration of A.

C. at equilibrium, the concentration of C will be much greater than the

concentration of A or B.

D. C will rapidly break down to A + B.

E. when A and B are mixed, the reaction will proceed rapidly toward formation

of C.

29. Estimate the value of Km for an enzyme-catalyzed reaction for which the

following data points were obtained.

[S] (M) V0 (mM/min)

2.5 x 10-6 28

4.0 x 10-6 40

1.0 x 10-5 70

2.0 x 10-5 95

4.0 x 10-5 112

1.0 x 10-4 128

2.0 x 10-3 139

1.0 x 10-2 140

A. 1.0 x 10-4

B. 1.0 x 10-3

C. 1.0 x 10-6

D. 1.0 x 10-5

E. 1.0 x 10-7

30. pH = pKa when:

[A-]/[HA] = 0

log ([A-]/[HA]) = 1

[A-] >> [HA]

[A-] = [HA]

log ([HA]/[A-]) = 1

31. In the conversion of A into D in the following biochemical pathway, enzymes

EA, EB, and EC have the Km values indicated under each enzyme. If all of the

substrates and products are present at a concentration of 10-4 M and the

enzymes have approximately the same Vmax which step will be rate limiting?

Rx1 Rx2 Rx3

A ↔ B ↔ C ↔ D

EA EB EC

Km = 10-2M 10-4M 10-4M

A. Rx 3

B. Rx 1

C. Rx 2

D. Rx’s 1 and 3

E. Rx’s 2 and 3

32. Consider the following Keq values with the appropriate ΔG0’?

Keq ΔG0’

A 1.0 1 28.53

B 10-5 2 -11.42

C 104 3 5.69

D 102 4 0

E 10-1 5 -22.84

A Keq of 102 would correspond to which of the following ΔG0’ values?

28.53

-11.42

5.69

0

-22.84

33. For an enzyme that follows simple Michaelis-Menten kinetics, what is the

value of Vmax if V0 is equal to 1 µmol minute-1 when [S] = 1/10 Km?

11.0 µmol minute-1

1.10 µmol minute-1

0.10 µmol minute-1

10.1 µmol minute-1

1.0 µmol minute-1