How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction?
A) by binding to the active site of the enzyme, thus preventing binding of the normal substrate
B) by binding to an allosteric site, thus changing the shape of the active site of the enzyme
C) by decreasing the free-energy change of the reaction catalyzed by the enzyme
D) by increasing the activation energy of the reaction

Question

Quizplus · Accepted Answer

Noncompetitive inhibitors bind to an allosteric site (a site other than the active site) on an enzyme. This binding changes the shape of the enzyme, including the shape of the active site, which can prevent the substrate from binding effectively or alter the efficiency of the enzyme, thus decreasing the rate of the reaction.

How Does a Noncompetitive Inhibitor Decrease the Rate of an Enzyme-Catalyzed