Question

Question 14

1. What is the approximate Keq for this reaction?

GTP+TDP → GDP+TTP

		near 1
		0
		-1
		Not enough information was given.

Question 15

1. What is the approximate ∆G'° for this reaction?

GTP+TDP → GDP+TTP

		Near 0
		Near 1
		Near -1
		Not enough information was given.

Question 16

1. Succinate dehydrogenase, a critical enzyme in the tricarboxylic acid cycle. You are characterizing the possible inhibitor malonate and want to determine its mode of binding to succinate dehydrogenase. Equilibrium dialysis measurements at 25℃, 30℃, and 37℃ yielded dissociation constants (Ks) of 1.0 x 10⁻⁶ M, 1.5 x 10⁻⁶ , and 2.0 x 10⁻⁶ M, respectively, for the succinate dehydrogenase-inhibitor complex. Use this information to answer questions 16-17.

Is the binding becoming better or worse with the increasing temperature?

		Better because the Ks values are increasing with increasing temperature
		Better because the Ks values are decreasing with increasing temperature
		Worse because the Ks values are increasing with increasing temperature
		Worse because the Ks values are decreasing with increasing temperature

Question 17

1. If Vmax is unchanged with addition of inhibitor, what kind of inhibitor is malonate?

		Competitive
		Pure noncompetitive
		Mixed noncompetitive
		Uncompetitive
		Suicide substrate

Answer 1

1.) Keq (Equlibrium constant) of given reaction is less than 1 if reaction is spontaneous. So, in this case Keq is -1 because Keq equals to 0 for reaction at equlibrium.

2.) ∆G° is Change in Gibbs(Free) energy which can be calculated by difference between energy of reactant and product. For any spontaneous reaction ∆G° is negative. So, here in this case, near -1 is correct answer.

3.) Dissociation constant is increasing by increasing temperature.

4.) If Vmax remain unchanged that means the inhibitor is like substrate so the inhibitor is called as Competitive.