Question

What does the plot in the diagram depict?

(a) Variation in the apparent equilibrium constants of a one-substrate one-product reaction

(b) Variation in the apparent equilibrium constants of a two-substrate two-product reaction

(c) Variation in the apparent equilibrium constant and percentage yield

(d) pH dependence on apparent equilibrium constant

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I want to ask this question from Recent Advances in chapter Recent Advances in Enzyme Technology of Enzyme Technology

Answer 1

Right choice is (d) pH dependence on apparent equilibrium constant

To explain: The plot in the diagram depicts pH dependence on apparent equilibrium constant or the synthesis of N-Benzoyl-L-phenylalanine ethyl ester, as given by the reaction scheme. Red straight line represents reaction in aqueous solution only, whereas red dotted line reaction in a biphasic chloroform-water system. An upward shift is seen which is because of the more significant partitioning of the ester into the organic phase relative to the reactants. The shift in the pH dependence is higher pH is due to the change in the apparent pKa of the acid.