Ascorbic acid, found in citrus fruits, acts as an inhibitor to catecholase, the enzyme responsible for the browning reaction in fruits such as apples, peaches, and pears. One explanation for the inhibiting function of ascorbic acid could be its similarity, in terms of size and shape, to catechol, the substrate of the browning reaction. If this explanation is correct, then this inhibition is most likely an example of _______ inhibition.

Question

Quizplus · Accepted Answer

Ascorbic acid is acting as a competitive inhibitor of the enzyme catecholase by competing with the substrate, catechol, for binding to the active site of the enzyme. The size and shape similarity between ascorbic acid and catechol allow them to compete for the same binding site on the enzyme. This leads to a decrease in the rate of the browning reaction.

Ascorbic Acid, Found in Citrus Fruits, Acts as an Inhibitor