What are special proteins that catalyze chemical reactions called?

Special proteins that catalyze chemical reactions are known as enzymes. Enzymes are essential biological catalysts that accelerate chemical reactions in the body by lowering the activation energy required for reactions to occur. They are highly specific to their substrates, meaning that each enzyme only reacts with particular molecules, which allows for the precise regulation of metabolic pathways in biological systems.

The role of enzymes is crucial in both catabolic and anabolic processes—breaking down substances to release energy or synthesizing new compounds necessary for cellular function and growth. Without enzymes, many vital biochemical reactions would happen far too slowly to support life.

In contrast, hormones are signaling molecules that regulate physiological processes, antibodies are proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses, and receptors are proteins that bind to specific molecules to initiate cellular responses. Each of these plays a significant role in biological functions but does not serve the catalytic role that enzymes do.