Which statement about drug-receptor interactions is most accurate?

Which statement about drug-receptor interactions is most accurate?

• A. The induced fit model acknowledges some flexibility and shape change upon binding
• B. The lock and key model is the sole explanation
• C. Receptors never change shape
• D. Binding occurs only at allosteric sites

Answer: (A)

Drug-receptor interactions are dynamic, not perfectly rigid. The induced fit concept captures this by showing that receptors can adjust their shape slightly to accommodate a bound drug, creating better contact and a more stable complex. This flexibility helps explain why some ligands provoke changes in receptor activity after binding and why binding can be more favorable when the receptor is allowed to adapt. The lock-and-key idea, while historically useful, is too simplistic because it envisions a fixed, exact fit with no shape change. In reality, receptors often undergo conformational changes upon ligand contact. Receptors do change shape, so the notion that they never alter their structure isn’t accurate. And binding isn’t restricted to allosteric sites; many drugs bind at the primary active (orthosteric) site, though allosteric sites exist and can modulate receptor behavior. Taken together, the statement about induced fit best reflects how drug-receptor interactions actually occur.

Drug-receptor interactions are dynamic, not perfectly rigid. The induced fit concept captures this by showing that receptors can adjust their shape slightly to accommodate a bound drug, creating better contact and a more stable complex. This flexibility helps explain why some ligands provoke changes in receptor activity after binding and why binding can be more favorable when the receptor is allowed to adapt. The lock-and-key idea, while historically useful, is too simplistic because it envisions a fixed, exact fit with no shape change. In reality, receptors often undergo conformational changes upon ligand contact. Receptors do change shape, so the notion that they never alter their structure isn’t accurate. And binding isn’t restricted to allosteric sites; many drugs bind at the primary active (orthosteric) site, though allosteric sites exist and can modulate receptor behavior. Taken together, the statement about induced fit best reflects how drug-receptor interactions actually occur.