Induced Fit Theory

 The Induced Fit Theory is a model that describes how enzymes and substrates interact during a biochemical reaction. Proposed by Daniel Koshland in 1958, this theory refines the earlier "lock and key" model of enzyme activity. According to the Induced Fit Theory:

1. Flexible Active Site: Unlike the rigid lock-and-key model, the enzyme's active site is flexible and can change its shape when interacting with a substrate.
2. Enzyme-Substrate Interaction: When a substrate approaches the enzyme, the enzyme undergoes a conformational change to better accommodate the substrate. This change improves the binding specificity and the catalytic efficiency of the enzyme.
3. Dynamic Process: The interaction between the enzyme and the substrate induces structural changes in both the enzyme and the substrate, aligning them for optimal binding and catalytic action.
4. Stabilization of Transition State: Once the substrate is bound, the enzyme stabilizes the transition state of the substrate, lowering the activation energy required for the reaction to proceed.

This theory emphasizes the dynamic nature of enzyme-substrate binding and accounts for the high specificity and efficiency seen in enzymatic reactions.