The mentioned assumptions and definitions regarding the Michaelis-Menten model lead to the Michaelis-Menten equation (for a more detailed derivation, see below), where km = (k-1 + k2) / k1, and where the "0" in v0 implies that this equation is only valid for describing the initial rates, where no significant amount of product has been formed. The 2 constants Vmax and km will be described on the following pages.

V0 = Vmax[S]/Km+[S]

Of course, the assumptions regarding the model do not apply to all enzymatic reactions; therefore, it is sometimes necessary to use more complicated models to describe them. However, the Michealis-Menten equation applies to many different enzymatic reactions, often involving several more steps than the 2-step mechanism proposed by Michaelis and Menten. Thus, enzymes that show a hyperbolic relationship between v0 and [S] are said to follow Michaelis-Menten kinetics. [1]


  1. Lehninger, Albert L.; Nelson, David L.; Cox, Michael M. (2008). Principles of Biochemistry (5th ed.). New York, NY: W.H. Freeman and Company. ISBN 978-0-7167-7108-1.

Reaction rate

Theory overview