The molecules which serve as chemicals to make reactions work, such as the breakdown of food molecules, are called enzymes. Enzymes are specialised proteins that act as catalysts in biochemical reactions, enabling them to occur at much faster rates under mild conditions. They work by lowering the activation energy required for a reaction to occur without being consumed in the process. Enzymes are essential for life and are involved in almost all biological processes, including the digestion of food, the metabolism of nutrients, and the synthesis of new molecules.