What is the main tenet of the lock-and-key model for drug activity?

Question

Quizplus · Accepted Answer

The main tenet of the lock-and-key model for drug activity is that there is a connection between the molecular structure of a drug and its biological effect. This model suggests that drugs act like keys that fit into specific "locks" on enzymes or receptors, leading to a biological response.

Answer: B 
 While there is a connection between molecular structure and biological activity in the lock-and-key model, the key feature is that only certain biological keys (i.e. the drug itself) can unlock the potential of a drug. This key-lock relationship is what determines drug specificity and selectivity.

Answer: C and D are incorrect 
 Choice C ("The key to a drug's success is to keep it locked away from stomach acid") is not a main tenet of the lock-and-key model, as it does not relate to the interaction of a drug with its biological target. Choice D ("The biological lock of an enzyme can be activated by using certain chemical keys") is partly correct, but incomplete - the lock-and-key model suggests that enzymes or receptors are "locked" in a certain conformation until a drug (the "key") binds and induces a conformational change that leads to a biological response.

What Is the Main Tenet of the Lock-And-Key Model for Drug