In the study of enzyme kinetics, the units Km and Vmax are measurements used to represent the rate of enzymatic reactions. Typically Vmax represents the maximum reaction rate achieved by the system, while Km is the substrate concentration at half the reaction rate of Vmax.
Enzyme kinetics is an essential part of biochemistry because enzymes are the protein catalysts that speed the rate of chemical reactions. The effect is achieved as the enzyme temporarily binds to the substrate and lowers the amount of activation energy required to convert the chemical.
Enzyme conversion rates are influenced by several other factors, including the concentration of substrate molecules, the presence of inhibitors and the temperature of the solution. The study of these rates is known as enzyme kinetics.
- Vmax represents the maximum rate of conversion achieved by a chemical system, and the rate is measured alongside the concentration of the substrate, the molecule upon which the enzyme acts.
- Km represents the molecule concentration when the reaction rate is exactly half of the Vmax rate.
The system of measurement used is known as Michaelis-Menten kinetics, and it is named for the German biochemist Leonor Michaelis and the pioneering Canadian physician Maud Menten, who both made significant contributions to the study of enzyme kinetics and histochemistry.