What term is used to describe the model that describes the enzyme active site adapting to fit the substrate?

The induced fit model is the correct term that describes how the enzyme's active site adapts to accommodate the substrate. In this model, the interaction between the enzyme and substrate is dynamic; the active site of the enzyme can undergo a conformational change to better fit the substrate after it initially binds. This flexibility in the enzyme structure enhances the binding affinity and facilitates the catalysis of the chemical reaction.

The induced fit model emphasizes that the enzyme's active site is not a rigid structure but rather has the ability to mold itself around the substrate, ultimately stabilizing the transition state and lowering the activation energy required for the reaction to proceed. This model contrasts with the lock and key model, which suggests a more static and complementary fit between the enzyme and substrate without significant alteration of the enzyme structure.

This concept is fundamental in biochemistry as it illustrates how enzymes can be highly selective and efficient in catalyzing specific reactions by adapting their shape in response to substrate binding. Understanding this model is crucial for applications such as drug design, where inhibitors may work by fitting into the active site or influencing the flexibility of the enzyme.