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Record Information
Version3.6
Creation Date2006-08-16 13:52:05 UTC
Update Date2014-07-30 19:21:07 UTC
HMDB IDHMDB01362
Secondary Accession NumbersNone
Metabolite Identification
Common NameHydrogen
DescriptionHydrogen 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
Synonyms
  1. Dihydrogen
  2. Hydrogen gas
Chemical FormulaH2
Average Molecular Weight2.01588
Monoisotopic Molecular Weight2.015650064
IUPAC Namedihydrogen
Traditional Namedihydrogen
CAS Registry Number1333-74-0
SMILES
[H][H]
InChI Identifier
InChI=1S/H2/h1H
InChI KeyUFHFLCQGNIYNRP-UHFFFAOYSA-N
Chemical Taxonomy
KingdomInorganic Compounds
Super ClassHomogeneous Non-metal Compounds
ClassOther Non-metal Organides
Sub ClassOther Non-metal Hydrides
Other Descriptors
  • a small molecule(Cyc)
  • inorganic molecular entity(ChEBI)
  • nonmetal atom(ChEBI)
  • s-block element atom(ChEBI)
Substituents
  • N/A
Direct ParentOther Non-metal Hydrides
Ontology
StatusExpected and Not Quantified
Origin
  • Endogenous
  • Microbial
Biofunction
  • Osmolyte, enzyme cofactor, signalling
ApplicationNot Available
Cellular locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
  • Nucleus
  • Lysosome
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisome
Physical Properties
StateLiquid
Experimental Properties
PropertyValueReference
Melting Point-259.2 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility0.00162 mg/mL at 21 °CNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
Physiological Charge0ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity0 m3·mol-1ChemAxon
Polarizability0.74 Å3ChemAxon
Spectra
SpectraNot Available
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Mitochondria
  • Nucleus
  • Lysosome
  • Endoplasmic reticulum
  • Golgi apparatus
  • Peroxisome
Biofluid LocationsNot Available
Tissue LocationNot Available
Pathways
NameSMPDB LinkKEGG Link
Carnitine SynthesisSMP00465Not Available
Catecholamine BiosynthesisSMP00012map00350
Degradation of SuperoxidesSMP00468Not Available
Ethanol DegradationSMP00449Not Available
Homocysteine DegradationSMP00455Not Available
Mitochondrial Beta-Oxidation of Long Chain Saturated Fatty AcidsSMP00482Not Available
Mitochondrial Beta-Oxidation of Medium Chain Saturated Fatty AcidsSMP00481Not Available
Mitochondrial Beta-Oxidation of Short Chain Saturated Fatty AcidsSMP00480Not Available
Mitochondrial Electron Transport ChainSMP00355map00190
Plasmalogen SynthesisSMP00479Not Available
Pyruvaldehyde DegradationSMP00459Not Available
Threonine and 2-Oxobutanoate DegradationSMP00452Not Available
Transfer of Acetyl Groups into MitochondriaSMP00466Not Available
Trehalose DegradationSMP00467Not Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB016247
KNApSAcK IDNot Available
Chemspider ID762
KEGG Compound IDC00282
BioCyc IDALPHA-GLUCOSE-16-BISPHOSPHATE
BiGG ID33778
Wikipedia LinkHydrogen
NuGOwiki LinkHMDB01362
Metagene LinkHMDB01362
METLIN IDNot Available
PubChem Compound783
PDB IDNot Available
ChEBI ID18276
References
Synthesis ReferenceAit-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 ReferencesNot Available

Enzymes

General function:
Involved in ion channel activity
Specific function:
Mediates the voltage-dependent proton permeability of excitable membranes. Forms a proton-selective channel through which protons may pass in accordance with their electrochemical gradient. Proton efflux, accompanied by membrane depolarization, facilitates acute production of reactive oxygen species in phagocytosis
Gene Name:
HVCN1
Uniprot ID:
Q96D96
Molecular weight:
31682.9