JEE Main levelSingle correct optionDifficulty 2 of 3el009
Match List I with List II. List I: P agonist; Q receptor antagonist; R competitive enzyme inhibitor; S allosteric enzyme inhibitor. List II: 1 binds a receptor and blocks the messenger without switching the receptor on; 2 binds a receptor and produces the response of the messenger; 3 binds the active site of an enzyme and resembles the substrate; 4 binds an enzyme away from the active site and changes the shape of that site.
AP-1, Q-2, R-3, S-4
BP-2, Q-1, R-4, S-3
CP-3, Q-4, R-2, S-1
DP-2, Q-1, R-3, S-4
Answer: D
An agonist activates a receptor (2), an antagonist only blocks it (1). A competitive inhibitor resembles the substrate and occupies the active site (3). An allosteric inhibitor acts at a distant site (4). So P-2, Q-1, R-3, S-4.