Protein catabolism

Protein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerisation into new proteins via the use of ribonucleic acids (RNA) and ribosomes. Protein catabolism, which is the breakdown of macromolecules, is essentially a digestion process.

Protein catabolism most commonly carried out by non-specific endo- and exo-proteases. However specific proteases are used for cleaving of proteins for regulatory and protein trafficking purposes.

The amino acids produced by catabolism may be directly recycled, used to make new amino acids, or be converted to other compounds via the Krebs Cycle.

See also: amino acid synthesis.