Question

Noncompetitive inhibition of enzymes

A. occurs when a substance other than the correct substrate binds at the active site of an enzyme.
B. occurs when a substance binds to an enzyme at a site away from the active site.
C. occurs by denaturation of an enzyme.
D. occurs by blocking the production of an enzyme.
E. occurs when two enzymes bind together.

Answer 1

Noncompetitive inhibition of enzymes occurs when an inhibitor molecule binds to an allosteric site and blocks substrate binding to the active site, reducing the enzyme's activity.

Step-by-step explanation:

Noncompetitive inhibition of enzymes occurs when an inhibitor molecule binds to the enzyme in a location other than the active site, known as the allosteric site. This binding induces a conformational change in the enzyme that blocks substrate binding to the active site. As a result, the enzyme's activity is reduced.

Unlike competitive inhibition where the inhibitor competes with the substrate for the active site, noncompetitive inhibition does not require a structural similarity between the inhibitor and substrate. Thus, the addition of excess substrate does not reverse the inhibitory effect in noncompetitive inhibition.