The effect of the accumulation of P, the reaction product, on the Michaelis-Menten equatio...

The effect of the accumulation of P, the reaction product, on the Michaelis-Menten equation

Equation 13.9 presents the simple Michaelis-Menten situation where the reaction is considered to be irreversible ([P] is negligible). Many enzymatic reactions are reversible, and P does accumulate.

a. Derive an equation for v, the rate of the enzyme-catalyzed reaction S→P in terms of a modified Michaelis-Menten model that incorporates the reverse reaction that will occur in the presence of product, P.

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b. Solve this modified Michaelis-Menten equation for the special situation when v = 0 (that is, is at equilibrium, or in other words, Keq = [P]/[S]). (J. B. S. Haldane first described this reversible Michaelis-Menten modification, and his expression for Keq in terms of the modified M-M equation is known as the Haldane relationship.)