Question

Which stage is preferred for the estimation of the rate of enzymatic reaction?

(a) Initial

(b) Mid

(c) Final

(d) Stationary

This question was posed to me in an online quiz.

This interesting question is from Determining Enzyme Kinetic Constants from Batch Data topic in division Homogenous Reactions of Bioprocess Engineering

Answer 1

The correct choice is (a) Initial

Explanation: Typically, only initial rate data are used. This means that several batch experiments are carried out with different initial substrate concentrations; from each set of data the reaction rate is evaluated at time zero. Initial rates and corresponding initial substrate concentrations are used as (v, s) pairs which can then be plotted in various ways for determination of vmax and Km. Initial rate data are preferred for enzyme reactions because experimental conditions such as enzyme and substrate concentrations are known most accurately at the start of the reaction.