Which of the following about Michaelis-Menten kinetics (m-M) are true?

Question

(A) It is applied when the steady-state assumption is hold. 

(B) kcat (or k2 above) is called turnover number.

(C) KM is numerically equal to the affinity between the substrate and the enzyme.

(D) The value of Vmax remains constant when the concentration of total enzyme doubles.

(E) The value of KM doubles when the concentration of total enzyme doubles.

Please explain the correct answer.

Answer 1

(B) kcat (or k2 above) is called turnover number. This is true because the kcat is the rate constant for conversion of ES to P and thus represents the number of substrate molecules converted to product per unit of time when the enzyme is saturated with substrate.