Vmax

From WikiMD's Wellness Encyclopedia

Vmax (or V_max) is a term used in enzyme kinetics to denote the maximum rate of an enzyme-catalyzed reaction. It is the rate of the reaction when the enzyme is saturated with the substrate. The term Vmax is derived from the Michaelis-Menten kinetics, which is a model for the kinetics of a simple enzyme-catalyzed reaction.

Overview[edit | edit source]

Vmax is a measure of the amount of product that can be formed by an enzyme in a given amount of time under saturating conditions of substrate concentration. It is a theoretical maximum rate of reaction, which can only be approached under ideal conditions. The actual rate of an enzyme-catalyzed reaction is usually less than the Vmax because the substrate concentration is not usually high enough to saturate the enzyme.

Calculation[edit | edit source]

Vmax can be calculated from the Michaelis constant (Km) and the enzyme concentration ([E]) using the following equation:

Vmax = kcat[E]

where kcat is the turnover number of the enzyme, which is the maximum number of substrate molecules an enzyme molecule can convert to product per unit time.

Factors affecting Vmax[edit | edit source]

Vmax is affected by several factors including the enzyme concentration, the substrate concentration, the temperature, the pH, and the presence of any inhibitors or activators.

See also[edit | edit source]

References[edit | edit source]

Vmax Resources

Contributors: Prab R. Tumpati, MD