Question

The monod equation is based on which type of kinetics?

(a) Zero order kinetics

(b) First-order kinetics

(c) Second order kinetics

(d) First-zero order kinetics

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I'd like to ask this question from Kinetics of Cell Substrate Uptake in Cell Culture topic in division Homogenous Reactions of Bioprocess Engineering

Answer 1

The correct choice is (d) First-zero order kinetics

Easiest explanation: Biochemical reactions involving a single substrate are often assumed to follow Michaelis–Menten kinetics, without regard to the model’s underlying assumptions. The Michaelis-Menten relationship for the effect of substrate concentration on the rate of an enzyme catalysed reaction is given by the equation:

\(V = \frac{V_{max}S}{(S+K_m)}\)

where V = rate of reaction, Vmax = maximal rate of reaction, S = substrate concentration, and Km = substrate concentration at which reaction rate = 0.5 Vmax.

The analogous Monod equation for effect of substrate concentration on the specific growth rate of a microorganism is as follows:

\(\mu = \frac{\mu_{max}S}{(S+K_s)}\)

where μ = specific growth rate, μmax = maximum specific growth rate in absence of substrate limitation, S = concentration of growth limiting substrate, Ks = substrate concentration which allows the organism to grow at 0.5 μmax.