Topic overview

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Enzyme activity depends on the interaction between a substrate and an active site, described by lock-and-key and induced-fit models. Michaelis–Menten kinetics relates reaction velocity to substrate concentration, while Km, Vmax, and kcat characterize aspects of enzyme behavior. Inhibitors can affect these kinetic parameters in different ways, and Lineweaver–Burk plots provide a method for examining them. Enzymes are also regulated through allosteric effectors, covalent modification, and proteolytic activation of zymogens. Cofactors and coenzymes support some reactions, while temperature and pH influence activity. The lesson also connects enzyme classes and isoenzymes with metabolic control and clinical interpretation.