Definition of catabolism in US English:



  • The breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism.

    • ‘During normal catabolism, protease enzymes break down carboxylase enzymes and reclaim the associated amino acids and biocytin for recycling.’
    • ‘The various reactions which involve the synthesis of complex molecules can be grouped under the heading of anabolism, whereas the breakdown of complex molecules is known as catabolism.’
    • ‘Ammonium produced by catabolism of protein is then excreted in urine.’
    • ‘Muscle catabolism is a hallmark of sepsis and results from accelerated breakdown of myofibrillar proteins, such as actin and myosin.’
    • ‘The process, in which the body basically metabolizes itself, is called catabolism and leads to muscle loss and weakness.’


Late 19th century: from Greek katabolē ‘throwing down’, from kata- ‘down’ + ballein ‘to throw’.