What is the term for the substance upon which an enzyme acts?

The term for the substance upon which an enzyme acts is "substrate." Enzymes are biological catalysts that speed up chemical reactions in living organisms, and they do this by binding to specific molecules called substrates. When an enzyme and its substrate interact, they form an enzyme-substrate complex. This complex facilitates the conversion of the substrate into products of the reaction.

The precise interaction between an enzyme and its substrate is crucial for the enzyme's function, as enzymes are designed to recognize specific substrates based on their shape and chemical properties. Understanding the role of the substrate is fundamental to biochemistry and is essential when studying metabolic pathways and enzyme kinetics.

The other terms refer to different aspects of enzymatic reactions: reactants are the starting materials in a chemical reaction, products are the substances produced as a result of the reaction, and inhibitors are molecules that decrease or prevent enzyme activity.