Human Metabolome Database Version 3.5

Showing metabocard for Hydrogen (HMDB01362)

Record Information
Version 3.5
Creation Date 2006-08-16 07:52:05 -0600
Update Date 2013-02-08 11:20:55 -0700
Secondary Accession Numbers None
Metabolite Identification
Common Name Hydrogen
Description Hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H2. With an atomic weight of 1.00794, hydrogen is the lightest element. Besides the common H1 isotope, hydrogen exists as the stable isotope Deuterium and the unstable, radioactive isotope Tritium. Hydrogen is the most abundant of the chemical elements, constituting roughly 75% of the universe's elemental mass. Hydrogen can form compounds with most elements and is present in water and most organic compounds. It plays a particularly important role in acid-base chemistry, in which many reactions involve the exchange of protons between soluble molecules. Oxidation of hydrogen, in the sense of removing its electron, formally gives H+, containing no electrons and a nucleus which is usually composed of one proton. That is why H+ is often called a proton. This species is central to discussion of acids. Under the Bronsted-Lowry theory, acids are proton donors, while bases are proton acceptors. A bare proton H+ cannot exist in solution because of its strong tendency to attach itself to atoms or molecules with electrons. However, the term 'proton' is used loosely to refer to positively charged or cationic hydrogen, denoted H+. H2 is a product of some types of anaerobic metabolism and is produced by several microorganisms, usually via reactions catalyzed by iron- or nickel-containing enzymes called hydrogenases. These enzymes catalyze the reversible redox reaction between H2 and its component two protons and two electrons. Creation of hydrogen gas occurs in the transfer of reducing equivalents produced during pyruvate fermentation to water.
Structure Thumb
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Display: 2D Structure | 3D Structure
  1. Dihydrogen
  2. Hydrogen
  3. Hydrogen cation
  4. Hydrogen gas
  5. Hydrogen ion
  6. Hydronium
  7. Proton
Chemical Formula H2
Average Molecular Weight 2.01588
Monoisotopic Molecular Weight 2.015650064
IUPAC Name dihydrogen
Traditional IUPAC Name dihydrogen
CAS Registry Number 1333-74-0
InChI Identifier InChI=1S/H2/h1H
Chemical Taxonomy
Kingdom Inorganic Compounds
Super Class Homogeneous Non-metal Compounds
Class Other Non-metal Organides
Sub Class Other Non-metal Hydrides
Other Descriptors
  • a small molecule(Cyc)
  • inorganic molecular entity(ChEBI)
  • nonmetal atom(ChEBI)
  • s-block element atom(ChEBI)
  • N/A
Direct Parent Other Non-metal Hydrides
Status Expected and Not Quantified
  • Endogenous
  • Microbial
  • Osmolyte, enzyme cofactor, signalling
Application Not Available
Cellular locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
  • Nucleus
  • Lysosome
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisome
Physical Properties
State Liquid
Experimental Properties
Property Value Reference
Melting Point -259.2 °C Not Available
Boiling Point Not Available Not Available
Water Solubility 0.00162 mg/mL at 21 °C Not Available
LogP Not Available Not Available
Predicted Properties
Property Value Source
Hydrogen Acceptor Count 0 ChemAxon
Hydrogen Donor Count 0 ChemAxon
Polar Surface Area 0 A2 ChemAxon
Rotatable Bond Count 0 ChemAxon
Refractivity 0 ChemAxon
Polarizability 0.74 ChemAxon
Formal Charge 0 ChemAxon
Physiological Charge 0 ChemAxon
Not Available
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
  • Nucleus
  • Lysosome
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisome
Biofluid Locations Not Available
Tissue Location Not Available
Name SMPDB Link KEGG Link
Mitochondrial Electron Transport Chain SMP00355 map00190 Link_out
Threonine and 2-Oxobutanoate Degradation SMP00452 Not Available
Homocysteine Degradation SMP00455 Not Available
Ethanol Degradation SMP00449 Not Available
Pyruvaldehyde Degradation SMP00459 Not Available
Carnitine Synthesis SMP00465 Not Available
Transfer of Acetyl Groups into Mitochondria SMP00466 Not Available
Trehalose Degradation SMP00467 Not Available
Degradation of Superoxides SMP00468 Not Available
Catecholamine Biosynthesis SMP00012 map00350 Link_out
Plasmalogen Synthesis SMP00479 Not Available
Mitochondrial Beta-Oxidation of Short Chain Saturated Fatty Acids SMP00480 Not Available
Mitochondrial Beta-Oxidation of Long Chain Saturated Fatty Acids SMP00482 Not Available
Mitochondrial Beta-Oxidation of Medium Chain Saturated Fatty Acids SMP00481 Not Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease References None
Associated OMIM IDs None
DrugBank ID Not Available
DrugBank Metabolite ID Not Available
Phenol Explorer Compound ID Not Available
Phenol Explorer Metabolite ID Not Available
FoodDB ID FDB016247
KNApSAcK ID Not Available
Chemspider ID 762 Link_out
KEGG Compound ID C00282 Link_out
BiGG ID 33778 Link_out
Wikipedia Link Hydrogen Link_out
NuGOwiki Link HMDB01362 Link_out
Metagene Link HMDB01362 Link_out
METLIN ID Not Available
PubChem Compound 783 Link_out
PDB ID Not Available
ChEBI ID 18276 Link_out
Synthesis Reference Ait-Ichou, I.; Formenti, M.; Pommier, B.; Teichner, S. J. Photocatalytic dehydrogenation of isopropanol on platinum/titania catalysts. Journal of Catalysis (1985), 91(2), 293-307.
Material Safety Data Sheet (MSDS) Not Available
General References Not Available

Name: Voltage-gated hydrogen channel 1
Reactions: Not Available
Gene Name: HVCN1
Uniprot ID: Q96D96 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA