What is the role of proteins that act as biological catalysts in chemical reactions?

Proteins that act as biological catalysts in chemical reactions are known as enzymes. Enzymes speed up the rate of chemical reactions in the body by lowering the activation energy required for the reaction to occur. They do this by providing an alternative reaction pathway. The unique structure of enzymes allows them to bind specifically to substrates, which are the reactants in the reaction that the enzyme acts upon. This binding creates an enzyme-substrate complex that facilitates the conversion of substrates into products.

In addition to their catalytic role, enzymes are also highly specific, meaning that a particular enzyme will typically only catalyze a specific reaction or set of reactions. This specificity is a key feature of enzymatic activity and is essential for maintaining the proper functioning of biological systems.

Other options, such as substrates, co-factors, and hormones, play different roles in biological processes. Substrates are the substances upon which enzymes act, co-factors assist enzymes in their activity (often by providing additional chemical groups or stabilizing structures), and hormones are signaling molecules that regulate physiological processes but do not catalyze reactions themselves.