Enzymes are biological catalysts, meaning they speed up chemical reactions without being consumed in the process. They are essential for virtually all biological processes, including:

* Digestion: Breaking down food molecules.

* Metabolism: Converting nutrients into energy and building blocks for cells.

* DNA replication: Copying genetic information.

* Immune response: Fighting off infections.

Each enzyme has a specific shape and structure that allows it to bind to a particular molecule called a substrate. This interaction facilitates the chemical reaction, making it happen much faster than it would on its own.