Second, Km is related to the rate constants of the individual steps in the catalytic scheme given in equation 14. In equation 20, KM is defined as (k2+ k3)/kl. Consider a limiting case in which k2 is much greater than ks. This means that dissociation of the ES complex to E and S is much more rapid than formation of E and product. Under these conditions (k2>k3) E+S ES E+P (14) 2 Equation 19 can be simplified by defining a new constant, KM, called the Michaelis constant k+ k KI M (20)