A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as ________.
A. A coenzyme.
B. An allosteric inhibitor.
C. The substrate.
D. An intermediate.
E. A competitive inhibitor.

Allosteric inhibitor is a specific type of inhibitor that binds to the target enzyme at a specific site that is remote from the active site thus modulating or inhibiting the activity of that enzyme.

Allosteric interraction is of 2 types

1 Homotropic Interraction when substrate itself is a modulator,then the Interration that occurs between enzymes and target enzyme is known as Homotropic Interraction.

2 Hetarotropic Interraction During Hetarotropic interraction inhibitor bind to the specific site of the target enzyme that is different from the active site thereby inhibiting the activity of the target enzyme.

Here the product A binds to the enzyme that converts X to Y and decreasing the activity of that enzyme .This inhibition is a perfect example of Hetarotropic Allosteric Interraction