National League for Nursing (NLN PAX) Practice Exam

Enzymes are classified as catalysts because they facilitate biochemical reactions by lowering the activation energy necessary for those reactions to occur. This ability allows enzymes to speed up reactions without being consumed in the process, meaning they can be used repeatedly. By providing an alternative pathway for the reaction, enzymes increase the rate at which substrates are converted into products, making them crucial for numerous biological processes, including metabolism and digestion.

In contrast, colloids refer to mixtures where one substance is dispersed evenly throughout another, while cathodes relate to electrodes through which electric current exits a polarized electrical device, and constants refer to unchanging values in equations. These terms do not pertain to the specific functional role of enzymes in biochemical reactions.