This reaction occurs slowly, if at all, in the absence of catechol oxidase. Here is an experimental setup to determine if catechol is present in potato extract. Before you do the experiment, make a prediction based on the hypothesis that catechol oxidase is present in potato extract. Explain your answer in a sentence or two. An inhibitor is a chemical that keeps an enzyme from catalyzing a reaction.
Inhibitors are of two different types.
Because the substrate is kept out of the site, the reaction does not occur. Noncompetitive inhibitors act elsewhere. For example, they may bind to another site on the enzyme and induce its shape to change in such a way that the active site no longer fits the substrate. A simple way to test to see whether an inhibitor is competitive or not is to add more substrate. Here is an experimental setup to see if the known inhibitor of catechol oxidase, PTU, acts a competitive or noncompetitive inhibitor.