The "induced fit" model is a concept in biochemistry that describes how enzymes and substrates interact. It is a refinement of the earlier "lock and key" model. According to the induced fit model, when a substrate binds to an enzyme, the enzyme undergoes a conformational change that enhances the fit between the enzyme and the substrate.
Key Features of the Induced Fit Model:
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Dynamic Interaction: Unlike the lock and key model, where the enzyme's active site is seen as a perfect match for the substrate, the induced fit model emphasizes that the enzyme and substrate are flexible. The binding of the substrate induces structural changes in the enzyme.
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Enhanced Catalysis: The conformational changes that occur upon substrate binding can bring catalytic groups into the proper orientation and proximity, thereby facilitating the biochemical reaction.
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Specificity and Affinity: The ability of the enzyme to undergo conformational changes allows for greater specificity and affinity for substrates, enabling the enzyme to selectively bind and catalyze reactions for particular substrates.
This model highlights the importance of protein flexibility in biological functions and emphasizes that enzyme-substrate interactions are not rigid, but rather adaptable and dynamic. This concept is fundamental for understanding enzyme kinetics, regulation, and the overall functioning of biological molecules.