macromolecule metabolic process macromolecule metabolism The chemical reactions and pathways involving macromolecules, any molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass. [database_cross_reference: GOC:mah] organismal macromolecule metabolism multicellular organismal macromolecule metabolic process http://purl.obolibrary.org/obo/go.owl biopolymer metabolic process organic substance metabolic process