When a substrate concentration is much greater than KM, the rate of catalysis is almost equal to: A) K_D B) k_cat. C) V_max. D) All of the above. E) None of the above.

Question

Quizplus · Accepted Answer

When the substrate concentration is much greater than KM, the enzyme is said to be saturated, and the reaction rate reaches its maximum limit, referred to as Vmax. At this point, all of the enzyme's active sites are bound to a substrate, and further increases in the substrate concentration would not increase the reaction rate. Therefore, the rate of catalysis is almost equal to Vmax. KD represents the dissociation constant, which is not directly related to the catalysis rate, while kcat is the turnover number, which is the maximum number of substrate molecules converted to product per enzyme molecule per unit time, and it is related to Vmax but not equal to it.

When a Substrate Concentration Is Much Greater Than KM, the Rate