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The Michaelis–Menten equation relates initial velocity to substrate concentration under steady-state conditions. Vmax represents the rate at enzyme saturation, while Km is the substrate concentration at half Vmax; kcat and kcat/Km describe turnover and catalytic efficiency. The relationship also explains first-order behavior at substrate concentrations well below Km and zero-order behavior at concentrations well above Km. A Lineweaver–Burk plot provides a linear representation. Inhibitors produce distinct changes in Km and Vmax, offering a way to compare mechanisms. Temperature and pH can alter measured activity, while allosteric enzymes may show sigmoidal rather than hyperbolic behavior and require models that account for cooperativity.