Record Information
Version2.0
Creation Date2012-05-31 13:50:50 -0600
Update Date2015-09-17 16:24:07 -0600
Secondary Accession Numbers
  • ECMDB01362
Identification
Name:Hydrogen (gas)
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. The transport of protons or hydrogen ions across the membrane(ie the creation of a proton gradient) is critical to the generation of energy (ATP) for all living cells.
Structure
Thumb
Synonyms:
  • Dihydrogen
  • Hydrogen
  • Hydrogen cation
  • Hydrogen gas
  • Hydrogen ion
  • Hydrogen molecule
  • Hydronium
  • Proton
Chemical Formula:H2
Weight:Average: 2.0159
Monoisotopic: 2.015650064
InChI Key:UFHFLCQGNIYNRP-UHFFFAOYSA-N
InChI:InChI=1S/H2/h1H
CAS number:1333-74-0
IUPAC Name:Not Available
Traditional IUPAC Name:Not Available
SMILES:[H][H]
Chemical Taxonomy
DescriptionThis compound belongs to the class of chemical entities known as other non-metal hydrides. These are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is belongs to the class of 'other non-metals'.
KingdomChemical entities
Super ClassInorganic compounds
ClassHomogeneous non-metal compounds
Sub ClassOther non-metal organides
Direct ParentOther non-metal hydrides
Alternative ParentsNot Available
Substituents
  • Other non-metal hydride
Molecular FrameworkNot Available
External Descriptors
Physical Properties
State:Liquid
Charge:0
Melting point:-259.2 °C
Experimental Properties:
PropertyValueSource
Water Solubility:0.00162 mg/mL at 21 oC [VENABLE,CS & FUWA,T (1922)]PhysProp
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
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Biological Properties
Cellular Locations:Cytoplasm
Reactions:
SMPDB Pathways:
2,3-dihydroxybenzoate biosynthesisPW000751 Pw000751Pw000751 greyscalePw000751 simple
Menaquinol biosythesisPW001897 Pw001897Pw001897 greyscalePw001897 simple
KEGG Pathways:
EcoCyc Pathways:
Concentrations
Not Available
Spectra
Spectra:
Spectrum TypeDescriptionSplash Key
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0udi-9000000000-0595c445077141efd7acView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0udi-9000000000-0595c445077141efd7acView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0udi-9000000000-0595c445077141efd7acView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0udi-9000000000-cbcf030cfea82ec88da3View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0udi-9000000000-cbcf030cfea82ec88da3View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0udi-9000000000-cbcf030cfea82ec88da3View in MoNA
References
References:
  • Kanehisa, M., Goto, S., Sato, Y., Furumichi, M., Tanabe, M. (2012). "KEGG for integration and interpretation of large-scale molecular data sets." Nucleic Acids Res 40:D109-D114. Pubmed: 22080510
  • Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590. Pubmed: 21097882
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
External Links:
ResourceLink
CHEBI ID29235
HMDB IDHMDB01362
Pubchem Compound ID5362549
Kegg IDC00282
ChemSpider ID4515072
WikipediaHydrogen
BioCyc IDHYDROGEN-MOLECULE
EcoCyc IDHYDROGEN-MOLECULE

Enzymes

General function:
Involved in catalytic activity
Specific function:
A phosphate monoester + H(2)O = an alcohol + phosphate
Gene Name:
phoA
Uniprot ID:
P00634
Molecular weight:
49438
Reactions
A phosphate monoester + H(2)O = an alcohol + phosphate.
General function:
Involved in formate dehydrogenase (NAD+) activity
Specific function:
Decomposes formic acid to hydrogen and carbon dioxide under anaerobic conditions in the absence of exogenous electron acceptors
Gene Name:
fdhF
Uniprot ID:
P07658
Molecular weight:
79373
Reactions
Formate + NAD(+) = CO(2) + NADH.
General function:
Involved in electron carrier activity
Specific function:
Probable electron transfer protein for hydrogenase 3
Gene Name:
hycB
Uniprot ID:
P0AAK1
Molecular weight:
21873
General function:
Involved in nickel cation binding
Specific function:
This is one of three E.coli hydrogenases synthesized in response to different physiological conditions. HYD1 is believed to have a role in hydrogen cycling during fermentative growth
Gene Name:
hyaB
Uniprot ID:
P0ACD8
Molecular weight:
66253
Reactions
H(2) + A = AH(2).
General function:
Involved in nickel cation binding
Specific function:
This is one of three E.coli hydrogenases synthesized in response to different physiological conditions. HYD2 is involved in hydrogen uptake
Gene Name:
hybC
Uniprot ID:
P0ACE0
Molecular weight:
62491
Reactions
H(2) + A = AH(2).
General function:
Involved in oxidoreductase activity, acting on NADH or NADPH
Specific function:
Specific function unknown
Gene Name:
hycE
Uniprot ID:
P16431
Molecular weight:
64980
General function:
Involved in electron carrier activity
Specific function:
Probable electron transfer protein for hydrogenase 3
Gene Name:
hycF
Uniprot ID:
P16432
Molecular weight:
20309
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
Specific function unknown
Gene Name:
hycG
Uniprot ID:
P16433
Molecular weight:
27999
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
This is one of three E.coli hydrogenases synthesized in response to different physiological conditions. HYD1 is believed to have a role in hydrogen cycling during fermentative growth
Gene Name:
hyaA
Uniprot ID:
P69739
Molecular weight:
40681
Reactions
H(2) + A = AH(2).
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
This is one of three E.coli hydrogenases synthesized in response to different physiological conditions. HYD2 is involved in hydrogen uptake
Gene Name:
hybO
Uniprot ID:
P69741
Molecular weight:
39652
Reactions
H(2) + A = AH(2).
General function:
Involved in oxidoreductase activity
Specific function:
Specific function unknown
Gene Name:
hyfJ
Uniprot ID:
P77453
Molecular weight:
15577
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
Specific function unknown
Gene Name:
hyfD
Uniprot ID:
P77416
Molecular weight:
51754
General function:
Involved in oxidoreductase activity, acting on NADH or NADPH
Specific function:
Specific function unknown
Gene Name:
hyfG
Uniprot ID:
P77329
Molecular weight:
63383
General function:
Involved in electron carrier activity
Specific function:
Probable b-type cytochrome
Gene Name:
hyaC
Uniprot ID:
P0AAM1
Molecular weight:
27597
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
Specific function unknown
Gene Name:
hyfF
Uniprot ID:
P77437
Molecular weight:
56766
General function:
Involved in electron carrier activity
Specific function:
Participates in the periplasmic electron-transferring activity of hydrogenase 2 during its catalytic turnover
Gene Name:
hybA
Uniprot ID:
P0AAJ8
Molecular weight:
36003
General function:
Involved in oxidoreductase activity, acting on NADH or NADPH
Specific function:
Specific function unknown
Gene Name:
hyfE
Uniprot ID:
P0AEW1
Molecular weight:
23361
General function:
Involved in metal ion binding
Specific function:
Probable b-type cytochrome
Gene Name:
hybB
Uniprot ID:
P37180
Molecular weight:
43602
General function:
Involved in oxidation-reduction process
Specific function:
Specific function unknown
Gene Name:
hyfC
Uniprot ID:
P77858
Molecular weight:
34359
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
Specific function unknown
Gene Name:
hyfI
Uniprot ID:
P77668
Molecular weight:
28101
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
Specific function unknown
Gene Name:
hyfB
Uniprot ID:
P23482
Molecular weight:
72582
General function:
Involved in NADH dehydrogenase (ubiquinone) activity
Specific function:
Specific function unknown
Gene Name:
hycC
Uniprot ID:
P16429
Molecular weight:
64076
General function:
Involved in electron carrier activity
Specific function:
Probable electron transfer protein for hydrogenase 4
Gene Name:
hyfH
Uniprot ID:
P77423
Molecular weight:
20159
General function:
Involved in electron carrier activity
Specific function:
Probable electron transfer protein for hydrogenase 4
Gene Name:
hyfA
Uniprot ID:
P23481
Molecular weight:
22154
General function:
Involved in oxidation-reduction process
Specific function:
Specific function unknown
Gene Name:
hycD
Uniprot ID:
P16430
Molecular weight:
33029

Transporters

General function:
Involved in transmembrane transporter activity
Specific function:
Uptake of galactose across the boundary membrane with the concomitant transport of protons into the cell (symport system)
Gene Name:
galP
Uniprot ID:
P0AEP1
Molecular weight:
50982
General function:
Involved in transporter activity
Specific function:
Responsible for melibiose transport. It is capable of using hydrogen, sodium, and lithium cations as coupling cations for cotransport, depending on the particular sugar transported (symport system)
Gene Name:
melB
Uniprot ID:
P02921
Molecular weight:
52217
General function:
Involved in ion channel activity
Specific function:
Proton-coupled chloride transporter. Functions as antiport system and exchanges two chloride ions for 1 proton. Probably acts as an electrical shunt for an outwardly-directed proton pump that is linked to amino acid decarboxylation, as part of the extreme acid resistance (XAR) response
Gene Name:
clcA
Uniprot ID:
B1XD25
Molecular weight:
50348
General function:
Involved in transporter activity
Specific function:
Involved in the import of threonine and serine into the cell, with the concomitant import of a proton (symport system)
Gene Name:
tdcC
Uniprot ID:
C4ZR30
Molecular weight:
48878
General function:
Involved in ion channel activity
Specific function:
Proton-coupled chloride transporter. Functions as antiport system and exchanges two chloride ions for 1 proton. Probably acts as an electrical shunt for an outwardly-directed proton pump that is linked to amino acid decarboxylation, as part of the extreme acid resistance (XAR) response
Gene Name:
clcA
Uniprot ID:
C4ZRP8
Molecular weight:
50348
General function:
Involved in transporter activity
Specific function:
Involved in the import of threonine and serine into the cell, with the concomitant import of a proton (symport system)
Gene Name:
tdcC
Uniprot ID:
P0AAD8
Molecular weight:
48878
General function:
Involved in transmembrane transporter activity
Specific function:
Uptake of arabinose across the boundary membrane with the concomitant transport of protons into the cell (symport system)
Gene Name:
araE
Uniprot ID:
P0AE24
Molecular weight:
51684
General function:
Involved in transmembrane transporter activity
Specific function:
Uptake of D-xylose across the boundary membrane with the concomitant transport of protons into the cell (symport system)
Gene Name:
xylE
Uniprot ID:
P0AGF4
Molecular weight:
53608
General function:
Involved in transporter activity
Specific function:
Proton symporter that senses osmotic shifts and responds by importing osmolytes such as proline, glycine betaine, stachydrine, pipecolic acid, ectoine and taurine. It is both an osmosensor and an osmoregulator which is available to participate early in the bacterial osmoregulatory response
Gene Name:
proP
Uniprot ID:
P0C0L7
Molecular weight:
54845
General function:
Involved in ion channel activity
Specific function:
Proton-coupled chloride transporter. Functions as antiport system and exchanges two chloride ions for 1 proton. Probably acts as an electrical shunt for an outwardly-directed proton pump that is linked to amino acid decarboxylation, as part of the extreme acid resistance (XAR) response
Gene Name:
clcA
Uniprot ID:
P37019
Molecular weight:
50348
General function:
Involved in transporter activity
Specific function:
Non-specific porin
Gene Name:
ompN
Uniprot ID:
P77747
Molecular weight:
41220
General function:
Involved in transporter activity
Specific function:
Uptake of inorganic phosphate, phosphorylated compounds, and some other negatively charged solutes
Gene Name:
phoE
Uniprot ID:
P02932
Molecular weight:
38922
General function:
Involved in transporter activity
Specific function:
OmpF is a porin that forms passive diffusion pores which allow small molecular weight hydrophilic materials across the outer membrane. It is also a receptor for the bacteriophage T2
Gene Name:
ompF
Uniprot ID:
P02931
Molecular weight:
39333
General function:
Involved in transporter activity
Specific function:
Forms passive diffusion pores which allow small molecular weight hydrophilic materials across the outer membrane
Gene Name:
ompC
Uniprot ID:
P06996
Molecular weight:
40368