metabolic process Note that metabolic processes do not include single functions or processes such as protein-protein interactions, protein-nucleic acids, nor receptor-ligand interactions. The chemical reactions and pathways, including anabolism and catabolism, by which living organisms transform chemical substances. Metabolic processes typically transform small molecules, but also include macromolecular processes such as DNA repair and replication, and protein synthesis and degradation. Wikipedia:Metabolism metabolism changing relationship between operands