Enzyme

Brief explanation of the term

Enzymes: The catalysts of metabolism. Here is the enzyme catalase. Photo: iStock.com/Leonid Andronov

The term "enzyme" refers to a substance capable of catalyzing biochemical reactions. Enzymes are protein molecules (peptides or proteins) composed of amino acids. They possess a primary, secondary, tertiary, and, among others, a quaternary structure.

They act as catalysts and lower the activation energy required for the biochemical reaction to convert substances. Enzymes have a defined three-dimensional structure and bind only to substances that have the appropriate structure. The binding works according to the lock-and-key principle.