Enzymes are specialized proteins that act as biological catalysts, meaning they speed up chemical reactions in living organisms without being consumed in the process. They do this by lowering the activation energy required for a reaction to occur, allowing it to proceed more quickly and efficiently under normal biological conditions.
Each enzyme is highly specific to the reaction it catalyzes and usually works on one particular substrate—the molecule it acts upon. The substrate binds to the enzyme’s active site, forming an enzyme-substrate complex, which facilitates the conversion into the product.
Enzymes are essential for nearly all biological processes, including:
- Digestion (e.g., amylase breaking down starch),
- DNA replication (e.g., DNA polymerase),
- Cellular respiration (e.g., ATP synthase),
- Detoxification (e.g., catalase breaking down hydrogen peroxide).
Without enzymes, life-sustaining chemical reactions would occur too slowly to support life.