Question

Characterization of the complete three-dimensional structure of a newly purified protein suggests that it catalyzes the breakdown of a large substrate. The protein consists of a single polypeptide chain. It has a large pocket that appears to be the binding site for the substrate and a smaller indentation that appears to be the binding site for a regulatory molecule. What do these structural observations suggest about the mechanism by which the activity of this protein is likely regulated?Choices:A) It is probably an enzyme that is regulated by noncompetitive inhibition.B) It is probably a multi-subunit enzyme that is regulated by allosteric regulation.C) It is probably an enzyme that is regulated by competitive inhibition.D) It is probably an enzyme that is regulated by cooperativity.

Answer 1

Answer:

A) It is probably an ezyme that is regulated by noncompetitive inhibition.

Explanation:

This protein is an enzyme that consists of a single polypeptide chain, this means that it doesn't have more subunits. The pocket is in the binding site for substrate or active site, and the indentation is a binding site for another molecule. This different molecule is a regulatory molecule or an inhibitor. In this scenario, the inhibitor binds to another site that is not the active site. When an inhibitor binds to a site away from the active site, it is said that this molecule acts as a noncompetitive inhibitor.