. "\"The chemical reactions and pathways involving the nonmetallic element sulfur or compounds that contain sulfur, such as the amino acids methionine and cysteine or the tripeptide glutathione.\" [GOC:ai]" . . "sulfur compound metabolic process" . "sulfur metabolism" . "sulphur metabolic process" . "sulphur metabolism" . "Reactome:REACT_27247 \"Sulfur compound metabolism, Mycobacterium tuberculosis\"" . "Wikipedia:Sulfur_metabolism" . .