What is the Difference Between Induced Fit and Lock and Key?

The induced fit and lock and key models are two theories that explain the mode of an enzyme's interaction with its substrate. The main differences between these two models are:

1. Flexibility of the enzyme's active site: In the induced fit model, the enzyme's active site is flexible and can undergo conformational changes when the substrate binds, forming a perfect fit between the substrate and the enzyme. In the lock and key model, the enzyme's active site is rigid and has a static shape that complements the substrate at the beginning.
2. Substrate binding: In the induced fit model, the binding of the substrate with the active site of the enzyme induces the modification of the active site. In contrast, the lock and key model suggests that the substrate and the active site of the enzyme are complementary in shape at the beginning of the interaction.
3. Specificity: The induced fit model can explain the binding of enzyme and substrate when they are not perfectly complementary, while the lock and key model explains the binding of perfectly matching or fitting substrates.

In summary, the induced fit model portrays the enzyme structure as more flexible and complementary to the substrate only after the substrate is bound, whereas the lock and key model portrays the enzyme as conformationally rigid and able to bond only to substrates that exactly fit the active site.

Comparative Table: Induced Fit vs Lock vs Key

The induced fit model and the lock and key model are two different theories that describe how an enzyme binds to its substrate. Here is a table comparing the key differences between the two models:

Both models are used to describe enzyme-substrate interactions and are important in understanding how enzymes increase the rate of biological reactions through binding. Overall, the main difference between the induced fit and lock and key models is the mechanism of substrate binding and how the enzyme's active site changes to fit the substrate.