What are biological catalysts, mainly proteins, that facilitate biochemical reactions known as?

Biological catalysts that facilitate biochemical reactions are known as enzymes. Enzymes play a crucial role in speeding up reactions by lowering the activation energy required for those reactions to occur. They do this by providing an active site where substrates—the molecules which enzymes act upon—can bind. The unique structure of each enzyme allows it to interact specifically with its corresponding substrate, making enzymes highly specific for the reactions they catalyze.

Enzymes are primarily proteins, and their activity can be influenced by various factors such as temperature, pH, and substrate concentration. This specificity and regulation are vital for maintaining biological processes within the living organism. The role that enzymes play is fundamental in metabolism, signaling pathways, and numerous biochemical processes essential for life.

While hormones act as signaling molecules and coenzymes assist enzymes in catalysis, their functions are distinct from the catalytic activity of enzymes. Substrates, on the other hand, are the reactants that enzymes act upon rather than the catalysts themselves. Therefore, enzymes are the correct answer, as they encompass the biological catalysts that facilitate biochemical reactions.