You do an experiment in the laboratory and add increasing amounts of substrate to a solution containing an enzyme and a pH buffer. You incubate the container at the optimal temperature for your enzyme. Each time you add more substrate, you measure the rate of the reaction. If you graph the results with substrate concentration on the x-axis and reaction rate on the y-axis, what will you find over time?
A) The rate of the reaction will proceed with a slope of 1 and continue in a linear fashion indefinitely or until you run out of reactants.
B) The rate of the reaction will increase rapidly, taper off, and plateau.
C) The rate of the reaction will increase slowly, plateau, and then drop sharply back to zero.
D) The resulting graph will be a perfect bell curve.
E) There is no way to predict what the graph will look like without more information.

Question

Quizplus · Accepted Answer

The rate of the reaction increases with substrate concentration up to a point, after which it plateaus. This occurs because the enzyme becomes saturated with substrate; once all active sites on the enzyme are occupied, adding more substrate cannot increase the rate further.

You Do an Experiment in the Laboratory and Add Increasing