Catabolism

Catabolism (/kəˈtæbəlɪzəm/) is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions.

The formation of these wastes is usually an oxidation process involving a release of chemical free energy, some of which is lost as heat, but the rest of which is used to drive the synthesis of adenosine triphosphate (ATP).

This molecule acts as a way for the cell to transfer the energy released by catabolism to the energy-requiring reactions that make up anabolism.

In recent decades, many more hormones with at least some catabolic effects have been discovered, including cytokines, orexin (known as hypocretin), and melatonin.

[citation needed] The word catabolism is from Neo-Latin, which got the roots from Greek: κάτω kato, "downward" and βάλλειν ballein, "to throw".