AP BIOLOGY

Detailed explanation-1: -In noncompetitive inhibition, the inhibitor binds at an allosteric site separate from the active site of substrate binding. Thus in noncompetitive inhibition, the inhibitor can bind its target enzyme regardless of the presence of a bound substrate.

Detailed explanation-2: -The noncompetitive inhibitor slows down the reaction rate, i.e. the rate of the product formation is less with inhibitor present than with inhibitor absent. This means that the active site is modified, but not disabled, by the presence of the inhibitor.

Detailed explanation-3: -Correct answer: Noncompetitive inhibition is characterized by a decrease in the maximum velocity (or efficacy) of an enzyme. Noncompetitive inhibitors bind irreversibly to the enzyme and prevent the substrate-enzyme activity. This decreases the efficacy of the enzyme.

Detailed explanation-4: -competitive inhibitors compete with the actual ligand for the binding site in protein whereas non-competitive inhibitors do not.