The Catalytic Constant kcat
- When an enzyme is saturated with substrate, the velocity of a catalyzed reaction will be at a maximum,
Vmax. The rate constant under these conditions is referred to as the catalytic constant,
kcat, and is defined as follows:
- kcat is also called the turnover number, because it refers to the maximum amount of
substrate molecules that can be converted to product by an enzyme in a given amount of time
- For a simple single-substrate reaction, the catalytic constant is simply equal to k2,
the rate constant in the second reaction step:
