MichaelisMentenligningen

The Michaelis-Menten equation is a fundamental concept in enzyme kinetics that describes the rate of enzymatic reactions as a function of substrate concentration. It was first proposed by Leonor Michaelis and Maud Menten in 1913. The equation is based on the assumption that an enzyme (E) binds reversibly to its substrate (S) to form an enzyme-substrate complex (ES), which then irreversibly breaks down to form product (P) and regenerate the enzyme. This can be represented by the following mechanism:

E + S <=> ES -> E + P

The Michaelis-Menten equation is expressed as:

v = (Vmax * [S]) / (Km + [S])

where:

v is the initial reaction velocity

Vmax is the maximum reaction velocity achieved when the enzyme is saturated with substrate

[S] is the substrate concentration

Km is the Michaelis constant, which represents the substrate concentration at which the reaction velocity is half of Vmax. It is a measure of the enzyme's affinity for its substrate; a lower Km indicates a higher affinity.

The equation is a hyperbolic relationship between reaction velocity and substrate concentration. At low substrate concentrations ([S] << Km), the velocity is approximately proportional to [S]. As substrate concentration increases, the velocity approaches Vmax asymptotically. The Michaelis-Menten equation is widely used to characterize enzyme behavior and to understand enzyme regulation. It is a simplified model and has limitations, particularly when dealing with complex enzyme mechanisms or allosteric enzymes.