Question

1.Suppose that two proteins, A and B, can associate with each other to form a complex.   You measure the dissociation constant at several different temperatures and find that as you heat up the sample, the Kd decreases. Does this mean that binding of A and B becomes more favorable or less favorable as the temperature increases?

2.Calculate the ΔG for ATP hydrolysis in a cell in which the [ATP]/[ADP] ratio had climbed to 100_1, while the Pi concentration remained at 10 mM. How does this compare to the ratio of [ATP]/[ADP] when the reaction is at equilibrium and the Pi concentration remains at 10 mM? What would be the value for ΔG when the reactants and products were all at standard conditions (1 M)?

3.The enzymes under cellular regulation are those whose reactions typically proceed under nonequilibrium conditions. What would be the effect of allosteric inhibition of an enzyme that operated close to equilibrium?

4.A noncompetitive inhibitor does not prevent the enzyme from binding its substrate. What will be the effect of increasing the substrate concentration in the presence of a noncompetitive inhibitor? Do you expect a noncompetitive inhibitor to affect the enzyme Vmax? KM? Explain briefly.

Answer 1