Understanding Vmax The theoretical maximal velocity z Vmax is a constant for a given enzyme z Vmax is the theoretical maximal rate of the reaction - but it is NEVER achieved z To reach Vmax would require that ALL enzyme molecules have tightly bound substrateUnderstanding Vmax The theoretical maximal velocity z Vmax is a constant for a given enzyme z Vmax is the theoretical maximal rate of the reaction - but it is NEVER achieved z To reach Vmax would require that ALL enzyme molecules have tightly bound substrate