has role is deprotonated form of independent continuant gas molecular entity carbon monoxide A one-carbon compound in which the carbon is joined only to a single oxygen. It is a colourless, odourless, tasteless, toxic gas. carbon oxide metabolite mitochondrial respiratory-chain inhibitor neurotransmitter vasodilator agent EC 1.9.3.1 (cytochrome c oxidase) inhibitor P450 inhibitor probe neurotoxin ligand carbon monoxide(1+) biomarker signalling molecule one-carbon compound mouse metabolite human metabolite