A competitive inhibitor
A) forms an irreversible complex with the active site of an enzyme
B) forms an irreversible complex with a site on an enzyme other than the active site.
C) decreases the maximal velocity of the reaction catalyzed by an enzyme.
D) competes with the substrate for the active site of an enzyme.
E) lowers the Km for the substrate.

Question

Quizplus · Accepted Answer

A competitive inhibitor mimics the substrate and competes for the active site of the enzyme, thereby reducing the proportion of enzyme molecules bound to the substrate and decreasing the maximal velocity of the reaction. It does not form an irreversible complex with the enzyme, and does not affect the Km of the enzyme.

A Competitive Inhibitor