Question

Which order represents Michelis-Menten kinetics?

(a) First-Second order

(b) Zero-First order

(c) Zero-Second order

(d) Second order

This question was addressed to me in homework.

This interesting question is from General Reaction Kinetics for Biological Systems in chapter Homogenous Reactions of Bioprocess Engineering

Answer 1

Correct choice is (b) Zero-First order

Easiest explanation: The kinetics of many biological reactions are either zero-order, first-order or a combination of these called Michaelis-Menten kinetics. The reaction order depends on the relative size of the two terms in the denominator. At low substrate concentration [S] <<KM, under these conditions the reaction rate varies linearly with substrate concentration [S] – First order kinetics. However at higher [S] with [S] >> KM, the reaction becomes independent of [S] – Zero order kinetics.