Compound

CO

Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)

Definition from MeSH (D002248), National Library of Medicine, read 2026-09-23. NLM revises MeSH; this copy may not reflect its current record.

CHEBI:17245ChEBI

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Structure

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A generated conformer of CO — one low-energy arrangement PubChem computed, not a measured structure. Hydrogens are not drawn; the formula counts them.

Class: Inorganic compound
Formula: CO
Mass: 28.01 g/mol
Charge: 0
InChIKey: UGFAIRIUMAVXCW-UHFFFAOYSA-N
SMILES: [C-]#[O+]
Look it up: ChEBI PubChem By InChIKey

Identity from ChEBI, geometry from PubChem. Not evidence.

What it touches on the way

Mechanistic reach

2 entities

2 entities reached.

0 reported hops2 assembled from the scaffold

What the reference databases state

Statements

2 statements

2 statements · 1 reference database · Subject: CO · Sources: Rhea

Order

CO is a substrate of ADI1ProteinRhea RHEA:14161Inferred only
CO is a substrate of PIRProteinRhea RHEA:15381Inferred only

Reactions

21 reactions

5proton+heme b+3NADPH(4-)+3dioxygenbiliverdin IXalpha+CO+iron(2+)+3water+3NADP(3-)
Catalysed by HMOX1 or HMOX2
Reaction pageLeft to rightBalancedEC 1.14.14.18cytosol
Human-GEM MAR01450CC BY 4.0Reference data
3FADH2+2proton+deoxyhemoglobin+3dioxygenbiliverdin IXalpha+CO+3FAD+Fe(3+)+globin+3water
Catalysed by HMOX1 or HMOX2
Reaction pageLeft to rightUnbalancedEC 1.14.14.18cytosol
Human-GEM MAR04763CC BY 4.0Reference data
1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one+dioxygen3-(methylthio)propionic acid+CO+formic acid+2proton
Catalysed by ADI1
Reaction pageLeft to rightBalancedEC 1.13.11.53cytosol
Human-GEM MAR05388CC BY 4.0Reference data
COCO
Reaction pageReversibleBalancedcytosol, extracellular space
Human-GEM MAR07798CC BY 4.0Reference data
CO
Reaction pageReversibleBalance undeterminableextracellular space
Human-GEM MAR09288CC BY 4.0Reference data
1,2-dihydroxy-5-(methylsulfanyl)pent-1-en-3-one+dioxygen3-(methylsulfanyl)propanoate+CO+formate+2hydron
Catalysed by ADI1
Reaction pageDirection not assertedBalanced
Rhea RHEA:14161CC BY 4.0Reference data
quercetin+dioxygen2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate+CO
Catalysed by PIR
Reaction pageDirection not assertedBalanced
Rhea RHEA:15381CC BY 4.0Reference data
CHEBI:16569+dioxygenN-formylanthranilic acid+CO+hydron
Reaction pageDirection not assertedBalanced
Rhea RHEA:17949CC BY 4.0Reference data
CO+2oxidized [2Fe-2S]-[ferredoxin]+water2reduced [2Fe-2S]-[ferredoxin]+carbon dioxide+2hydron
Reaction pageDirection not assertedBalance undeterminable
Rhea RHEA:21040CC BY 4.0Reference data
CHEBI:29216+dioxygenCHEBI:16803+CO+hydron
Reaction pageDirection not assertedBalanced
Rhea RHEA:21572CC BY 4.0Reference data
heme b+3reduced [NADPH--hemoprotein reductase]+3dioxygenbiliverdin IXalpha+CO+iron(2+)+3oxidized [NADPH--hemoprotein reductase]+3water+hydron
Catalysed by HMOX1 or HMOX2
Reaction pageLeft to rightBalance undeterminable
Rhea RHEA:21764CC BY 4.0Reference data
5-amino-1-(5-phospho-beta-D-ribosyl)imidazole+S-adenosyl-L-methionineCHEBI:58354+CO+5'-deoxyadenosine+formate+L-methionine+3hydron
Reaction pageDirection not assertedBalanced
Rhea RHEA:24840CC BY 4.0Reference data

Show the remaining 9

Other names

6 names

Resolves to: CO

Also called: [CO]C#OC≡O
Systematic name: carbon monooxidecarbon monoxidecarbon(II) oxide