Biological Catalysts - GCSE Biology Definition

Biological catalysts are proteins, known as enzymes, found in living organisms that speed up chemical reactions. Enzymes help vital processes like digestion and respiration happen more quickly and efficiently. They work by lowering the activation energy needed for a reaction to occur, allowing cells to carry out functions at normal body temperature. Each enzyme has a specific shape that fits its target molecule, called the substrate, often described using the lock and key model. This specificity means each enzyme usually catalyses only one particular type of reaction.