What term refers to the molecule that an enzyme acts upon?

The term that refers to the molecule that an enzyme acts upon is "substrate." Enzymes are biological catalysts that speed up chemical reactions in living organisms, and they are highly specific for their substrates. When the substrate binds to the enzyme's active site, it forms an enzyme-substrate complex. This interaction lowers the activation energy required for the chemical reaction, leading to the formation of products. Understanding this concept is crucial because it highlights the specificity and function of enzymes in biochemical processes, and it underscores the role of substrates in enzymatic reactions.