19. Please choose the incorrect one from the following descriptions about the Michaelis-Menten rate equation. (A) KM measures the substrate concentration at which the reaction rate is Vmax/2 (B) kcat is the turnover number that measures the rate of the catalytic process (C) The ratio kcat/KM is a convenient measure of enzyme efficiency (D) A noncompetitive inhibitor reduces the apparent Vmax. (E) A competitive inhibitor increases the apparent Kcat