Enzymes are not consumed in chemical reactions and can be used repeatedly. They act as biological catalysts that increase the rate of chemical reactions without being permanently altered or used up. After facilitating a reaction, enzymes remain unchanged and are free to catalyze subsequent reactions. This characteristic allows a small amount of enzyme to catalyze many reactions efficiently. Enzymes achieve this by lowering the activation energy required for reactions, but the enzyme itself is not changed or consumed during the process.
