This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacodynamics, Subject name: Pharmacology
[{'content': 'A drug that binds to a receptor at a site distinct from the active site and alters the affinity of the receptor for the endogenous ligand is a:- \nSelect and explain. \nA. Competitive antagonist, B. Inverse against, C. Paial agonist, D. Allosteric modulator', 'role': 'user'}, {'content': 'Answer: D \nExplanation: * Allosteric modulator that binds to a receptor at a site distinct from the active site and alters the affinity of the receptor for the endogenous ligand. * Competitive antagonist binds to the same site as that of agonist, produces surmountable effect i.e. effect of antagonist can be overcome by increasing concentration of agonist. * Inverse agonist and paial agonist also bind to the same site as that of the agonist.', 'role': 'assistant'}]