Michaelis-Menten kinetics: a standalone construct

Victor Henri first derived the equation in his 1903 work Lois générales de l'action des diastases (General laws of the action of diastases), and Leonor Michaelis and Maud Menten gave the definitive treatment in their 1913 paper Die Kinetik der Invertinwirkung (The kinetics of invertase action), whose two names the model now carries. Michaelis-Menten kinetics describes how fast an enzyme, a protein that speeds up a chemical reaction, turns its substrate, the molecule it acts on, into product: the reaction rate climbs with substrate concentration and then levels off toward a maximum, Vmax, as the enzyme becomes saturated. The curve is fixed by two parameters, Vmax and the Michaelis constant Km, where Km is the substrate concentration at which the reaction runs at half of Vmax, so a smaller Km marks an enzyme that reaches half speed at lower substrate levels. In 1925 George Briggs and John Haldane rederived the same equation from a steady-state assumption, broadening it beyond the original rapid-equilibrium argument. The model applies to a single enzyme acting on a single substrate under initial-rate conditions, and its two-parameter summary (Vmax, Km) remains the standard description of enzyme activity across biochemistry, pharmacology, and industrial catalysis.[1][2][3][4]

Unit

A two-parameter rate model (Vmax and Km) for a single enzyme acting on a single substrate

Recovery means

Not applicable

Measured by

Km and Vmax are estimated by fitting initial reaction rates measured across a range of substrate concentrations, historically by linearizations such as the Lineweaver-Burk plot and now by nonlinear regression