Chemistry Regents Practice Test 2026 - Free Chemistry Regents Practice Questions and Study Guide

Enzymes play a crucial role in biological reactions by acting as catalysts, which means they facilitate the reaction process without being consumed in the reaction. The correct response highlights that enzymes speed up reactions by lowering the activation energy, which is the minimum energy required for a reaction to occur.

By lowering the activation energy, enzymes allow reactants to be transformed into products more readily, significantly increasing the reaction rate. This is essential in biological systems where many reactions need to occur rapidly to sustain life. Enzymes achieve this by providing an alternative pathway for the reaction that requires less energy.

While other roles for substances in reactions exist—like certain reactants that take part in the reaction or substances that increase the activation energy—they do not accurately describe the function of enzymes. Thus, the emphasis on their role in decreasing activation energy highlights their importance in biochemistry and cellular processes.