Question

Statement A: Competitive reversible antagonists reduce the efficacy but not potency of agonists working at the same receptor.

Statement B: Competitive reversible antagonists cause their effects by binding to orthosteric sites on the receptor.
A) Both A and B are true statements, and B is the correct explanation of A.
B) Both A and B are true statements, but B is not the correct explanation of A.
C) Statement A is true, and Statement B is false.
D) Statement A is false, and Statement B is true.

Answer 1

Statement A is true, and Statement B is false. Competitive reversible antagonists reduce the efficacy but not potency of agonists working at the same receptor, but they do not cause their effects by binding to orthosteric sites on the receptor.

Step-by-step explanation:

Statement A is true and Statement B is false. Competitive reversible antagonists do reduce the efficacy but not the potency of agonists working at the same receptor. However, they do not cause their effects by binding to orthosteric sites on the receptor.

In competitive reversible antagonism, the antagonist competes with the agonist for binding to the receptor's active site. This competition decreases the binding of the agonist and reduces its efficacy, meaning that it produces a smaller response. However, the potency of the agonist, which refers to the concentration needed to produce a response, remains unchanged. Therefore, Statement A is true.

Competitive reversible antagonists bind to the same site as the agonist, known as the orthosteric site, on the receptor. This is in contrast to noncompetitive antagonists, which bind to allosteric sites on the receptor, which are separate from the active site. Therefore, Statement B is false.