The formation of an enzyme-substrate complex typically follows these steps:
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Substrate Binding: The substrate molecule approaches the active site of the enzyme. The active site has a specific shape and chemical environment that accommodates the substrate.
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Formation of Enzyme-Substrate Complex: The substrate binds to the active site of the enzyme, forming the enzyme-substrate complex (ES complex). This binding can involve various non-covalent interactions, such as hydrogen bonds, ionic bonds, and hydrophobic effects.
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Induced Fit: In many cases, the binding of the substrate induces a conformational change in the enzyme, which enhances the fit between the enzyme and the substrate. This is known as the "induced fit" model.
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Catalysis: The enzyme facilitates a chemical reaction, lowering the activation energy required for the reaction to occur. This can involve the stabilization of transition states and the formation of intermediates.
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Product Release: Once the reaction is complete, the products have a different shape and chemical properties than the substrate. The products are released from the active site, regenerating the free enzyme.
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Enzyme Recovery: The enzyme returns to its original state, ready to catalyze another reaction with a new substrate.
This sequence of steps highlights how enzymes interact with substrates to perform their catalytic functions.