Question

questions 15 and 16 refer to the following. researchers investigated the dynamics of a reaction catalyzed by an enzyme. the researchers prepared a series of reactions, each with the same concentration of enzyme but with different concentrations of substrate. the researchers measured the amount of product in each reaction mixture after 5 minutes. the results are shown in figure 1. figure 1 rate of an enzyme - catalyzed reaction 16. mark for review which of the following best describes how an increase in the concentration of substrate in the reaction mixture affected the frequency of enzyme - substrate interactions? a. the frequency of enzyme - substrate interactions decreased over all substrate concentrations. b. the frequency of enzyme - substrate interactions increased exponentially over all substrate concentrations. c. the frequency of enzyme - substrate interactions increased until all of the active sites were interacting with substrate. d. the frequency of enzyme - substrate interactions increased until all of the enzyme was depleted

Explanation:

Enzymes have active sites that bind to substrates. At low substrate concentrations, increasing substrate concentration leads to more enzyme - substrate interactions as there are available active sites. As substrate concentration increases further, the active sites of the enzymes start to get saturated. Once all the active sites are occupied (when the enzyme is saturated), adding more substrate will not increase the frequency of enzyme - substrate interactions because there are no free active sites left for the additional substrate molecules to bind to.

Answer:

C. The frequency of enzyme - substrate interactions increased until all of the active sites were interacting with substrate.