Question

Suppose we applied drug X before a known agonist and observe no effect. a. Can drug X be an agonist or an antagonist? b. Suppose we increased the dose of the agonist after application of drug X and still observed no effect, is drug X a competitive or a noncompetitive ligand? Explain your answer

Answer 1

If drug X applied before a known agonist has no effect, it suggests that drug X is an antagonist. If the dose of the agonist is increased after application of drug X and still no effect is observed, it suggests that drug X is a noncompetitive ligand.

Step-by-step explanation:

If drug X applied before a known agonist has no effect, it suggests that drug X is an antagonist. An agonist mimics the effects of a neurotransmitter, while an antagonist blocks or impedes the normal activity of a neurotransmitter. In this case, when drug X is applied before the agonist, it prevents the agonist from having its normal effect.

If the dose of the agonist is increased after application of drug X and still no effect is observed, it suggests that drug X is a noncompetitive ligand. A competitive ligand competes with the agonist for the same binding site on the receptor, while a noncompetitive ligand binds to a different site on the receptor and still prevents the agonist from having its effect.