How do Enzymes Function as Catalysts?
Enzymes are almost always globular proteins with a place on the surface where the enzyme can bind to the reactant(s). This “notch” is the active site, comprised of just a few amino acids. The remainder of the enzyme helps to maintain the integrity of the active site. The active site has a precise size, shape, and electrical charge that exactly complements the reactant(s) or substrate(s). Enzymes are highly specific. Each chemical reaction that occurs in cells has its own enzyme. Enzyme shape determines its function. When a substrate binds to the enzyme, it “fits” into the active site, temporarily distorting the reacting molecules, which is called the induced fit. This distorted stage of the substrate is called the transition state and its bonds are more easily broken (lowered activation energy), promoting the reaction. Once the reaction occurs, the active site is altered, releasing the product. The enzyme is unaffected by the reaction. In some cases, a substance can fit into the active
