When Is K_M Considered to Be the Same as the Dissociation

When is K_M considered to be the same as the dissociation constant for the ES complex i.e., K_M $\approx$ [E] [S] / [ES].

A) ES $\rarr$ E + P is fast compared to ES $\rarr$ E + S
B) the turnover number is very large
C) k_cat/K_M is near the diffusion-controlled limit
D) k₂ << k_-1
E) K_M can never be the same as the dissociation constant