AP BIOLOGY

Detailed explanation-1: -Limitations of the lock and key model This model does not explain the stabilization of the intermediate shape of the substrate. According to this model, the enzyme is a rigid structure and does not change its shape upon binding, which is not supported by recent research.

Detailed explanation-2: -The advantage of the lock-and-key model is that it explains why most enzymes display such high specificity to their substrates. Each enzyme will catalyse only a certain type of reaction and will only bind to a single specific substrate out of the millions of different molecules that are floating around our bodies.

Detailed explanation-3: -Correct answer: Explanation: The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.

Detailed explanation-4: -The theory was postulated by Emil Fisher in 1898. According to the hypothesis, like a lock can be open by its key only, a substance possessing specific composition only can combine with the specific active site found in the specific enzyme’s surface.