catabolism

[CATA- + (META)BOLISM.]

The metabolic breakdown of large molecules in living organisms to smaller ones, with the release of energy. Respiration is an example of a catabolic series of reactions. See metabolism. Compare anabolism.

Those pathways of metabolism concerned with the breakdown and oxidation of fuels and hence provision of metabolic energy. People who are undernourished or suffering from cachexia are sometimes said to be in a catabolic state, in that they are catabolizing their body tissues, without replacing them.

The destructive processes (opposite of the anabolic-metabolic processes) by which complex substances are converted into more simple compounds. A proper relation between anabolism and catabolism is essential for the maintenance of bodily homeostasis and dynamic equilibrium.

Chemical reactions which take place in the body and that result in the breakdown of large molecules into smaller ones. See also metabolism. Compare anabolism.

Biochemical reactions that break down molecules in metabolism. Molecules may be broken down to gain their energy or to prepare them for disposal from the body. (Compare anabolism.)

Any destructive process by which complex substances are converted by living cells into simpler compounds, with release of energy. See also metabolism.