And once we reach the V max, it doesn't matter if we add more of that substrate. Adding more substrate will not have any effect on the rate of that enzyme catalyzed reaction. And that can be seen from this equation. So v naught is equal to v max. V Naught is equal to V max is an equation that describes a rate law that has a 0th order. Remember, V is equal to K multiplied by the concentration to the 0th power.