Bicarbonate: Difference between revisions

{{About||baking soda|sodium bicarbonate|the programming principle|Tim Toady Bicarbonate}}{{Distinguish|Dicarbonate}}{{Redirect|Hydrogen carbonate|the oxoacid|carbonic acid}}{{redirect|Hydrocarbonate|the gas|water gas}}{{Chembox

| ImageSize1 = 121

| ImageName1 = Skeletal formula of bicarbonate with the explicit hydrogen added

| ImageFile2 = Bicarbonate-ion-3D-balls.png

| ImageSize2 = 121

| ImageName2 = Ball and stick model of bicarbonate

| SystematicName = Hydroxidodioxidocarbonate(1−)<ref name="hydrogencarbonate (CHEBI:17544)">{{Cite web|url = https://www.ebi.ac.uk/chebi/searchId.do?chebiId=17544|title = hydrogencarbonate (CHEBI:17544)|work = Chemical Entities of Biological Interest (ChEBI)|location = UK|publisher = European Institute of Bioinformatics|at = IUPAC Names|url-status = live|archiveurlarchive-url = https://web.archive.org/web/20150607062137/http://www.ebi.ac.uk/chebi/searchId.do?chebiId=17544|archivedatearchive-date = 2015-06-07}}</ref>

| OtherNames = Hydrogencarbonate{{Unbulleted list|Hydrogen carbonate<ref name = "hydrogencarbonate (CHEBI:17544)" />|Hydrocarbonate}}

| Section1 = {{Chembox Identifiers

|CASNo = 71-52-3
|CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = HN1ZRA3Q20

| PubChem = 769

| ChemSpiderID = 749

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| KEGG = C00288

| KEGG_Ref = {{keggcite|correct|kegg}}

| ChEBI = 17544

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 363707

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| Beilstein = 3903504

| Gmelin = 49249

| 3DMet = B00080

| SMILES = OC([O-])=O

| StdInChI = 1S/CH2O3/c2-1(3)4/h(H2,2,3,4)/p-1

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = BVKZGUZCCUSVTD-UHFFFAOYSA-M

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| Section2 = {{Chembox Properties

| Formula = {{Chem|HCO|3|-}}

| MolarMass = 61.0168 g mol⁻¹

| LogP = −0.82

| pKa = 10.3

| pKb = 7.7

| ConjugateAcid = [[Carbonic acid]]

| ConjugateBase = [[Carbonate]]

In [[inorganic chemistry]], '''bicarbonate''' ([[International Union of Pure and Applied Chemistry|IUPAC]]-recommended nomenclature: '''hydrogen carbonatehydrogencarbonate'''<ref>{{Citation|url = https://iupac.org/wp-content/uploads/2016/07/Red_Book_2005.pdf|title = Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005|publisher = IUPAC|page = 137}}</ref>) is an intermediate form in the [[deprotonation]] of [[carbonic acid]]. It is a [[Polyatomic ion|polyatomic]] [[anion]] with the chemical formula {{chem|[[Hydrogen|H]]|[[Carbon|C]]|[[Oxygen|O]]|3|-}}.

Bicarbonate serves a crucial biochemical role in the physiological [[pH]] [[buffering solution|buffering]] system.<ref name="veq">{{cite web | url = http://www.biology.arizona.edu/biochemistry/problem_sets/medph/intro.html | publisher = Biology.arizona.edu | date = October 2006 | title = Clinical correlates of pH levels: bicarbonate as a buffer | url-status = live | archiveurlarchive-url = https://web.archive.org/web/20150531000344/http://www.biology.arizona.edu/biochemistry/problem_sets/medph/intro.html | archivedatearchive-date = 2015-05-31 }}</ref>

The term "bicarbonate" was [[Factitious airs#bicarbonate|coined]] in 1814 by the English chemist [[William Hyde Wollaston]].<ref>William Hyde Wollaston (1814) "A synoptic scale of chemical equivalents,", ''Philosophical Transactions of the Royal Society'', '''104''': 1-22. [https://books.google.com/books?id=uYdJAAAAYAAJ&pg=PA11#v=onepage&q&f=false On page 11], Wollaston coins the term "bicarbonate": "The next question that occurs relates to the composition of this crystallized carbonate of potash, which I am induced to call bi-carbonate of potash, for the purpose of marking more decidedly the distinction between this salt and that which is commonly called a subcarbonate, and in order to refer at once to the double dose of carbonic acid contained in it."</ref> The prefix "bi" in "bicarbonate" comes from an outdated naming system and is based on the observation that there is twice as much [[carbonate]] ({{Chem|CO|3|2-}}) per sodium ion in [[sodium bicarbonate]] (NaHCO₃) and other bicarbonates than in [[sodium carbonate]] (Na₂CO₃) and other carbonates.<ref>{{cite web|url=http://www.newton.dep.anl.gov/askasci/chem99/chem99492.htm|title=Baking Soda|publisher=[[Argonne National Laboratory]]|website=Newton – Ask a Scientist|accessdateaccess-date=2 May 2018|url-status=dead|archiveurlarchive-url=https://web.archive.org/web/20150226223438/http://newton.dep.anl.gov/askasci/chem99/chem99492.htm|archivedatearchive-date=26 February 2015}}</ref> The name lives on as a [[trivial name]].

A bicarbonate salt forms when a [[cation|positively charged ion]] attaches to the negatively charged oxygen atoms of the ion, forming an [[ionic compound]]. Many bicarbonates are [[solubility|soluble]] in [[aqueous solution|water]] at [[standard temperature and pressure]]; in particular, sodium bicarbonate contributes to [[total dissolved solids]], a common parameter for assessing [[water quality]].<ref>{{citationcite neededbook|last1=Geor|first1=Raymond J.|last2=Coenen|first2=Manfred|last3=Harris|first3=Pat|title=Equine Applied and Clinical Nutrition: Health, Welfare and Performance|date=March31 January 2013|publisher=Elsevier Health Sciences|isbn=978-0-7020-5418-1|page=90|language=en|quote=The most common indicator of water quality is the concentration of total dissolved solids 2011(TDS)}}</ref>

Bicarbonate ({{Chem|HCO|3|-}}) is a vital component of the [[pH]] [[Buffer solution|buffering system]]<ref name="veq" /> of the human body (maintaining [[acid–base homeostasis]]). 70%–75% of CO₂ in the body is converted into [[carbonic acid]] (H₂CO₃), which is the [[conjugate acid]] of {{Chem|HCO|3|-}} and can quickly turn into it.{{cn|date=February 2024}}

With carbonic acid as the [[Reaction intermediate|central intermediate]] [[Chemical species|species]], bicarbonate – in conjunction with water, [[hydronium|hydrogen ions]], and [[carbon dioxide]] – forms this buffering system, which is maintained at the volatile equilibrium<ref name="veq" /> required to provide prompt resistance to pH changes in both the acidic and [[Base (chemistry)|basic]] directions. This is especially important for protecting [[Tissue (biology)|tissues]] of the [[central nervous system]], where pH changes too far outside of the normal range in either direction could prove disastrous (see [[acidosis]] or [[alkalosis]]). Recently it has been also demonstrated that cellular bicarbonate metabolism can be regulated by mTORC1 signaling.<ref>{{cite journal|vauthors = Ali E, Liponska A, O'Hara B, Amici D, Torno M, Gao P, Asara J, Yap M-N F, Mendillo M, Ben-Sahra I|title = The mTORC1-SLC4A7 axis stimulates bicarbonate import to enhance de novo nucleotide synthesis|journal = Molecular Cell|volume = 82|issue = 1|pages = 3284–3298.e7|date = June 2022|doi = 10.1016/j.molcel.2022.06.008|pmid = 35772404|pmc = 9444906}}</ref>

BicarbonateAdditionally, alsobicarbonate plays a serveskey muchrole in the digestive system. It raises the internal pH of the stomach, after highly acidic digestive juices have finished in their digestion of food. Bicarbonate also acts to regulate pH in the small intestine. It is released from the [[pancreas]] in response to the hormone [[secretin]] to neutralize the acidic [[chyme]] entering the [[duodenum]] from the stomach.<ref>Berne & Levy, ''Principles of Physiology''</ref>

Bicarbonate is the dominant form of [[Total inorganic carbon|dissolved inorganic carbon]] in sea water,<ref>{{cite web|title=The chemistry of ocean acidification : OCB-OA|url=http://www.whoi.edu/OCB-OA/page.do?pid=112136|website=www.whoi.edu|publisher=Woods Hole Oceanographic Institution|accessdateaccess-date=17 May 2017|language=en-NZ|date=24 September 2012|url-status=live|archiveurlarchive-url=https://web.archive.org/web/20170519193604/http://www.whoi.edu/OCB-OA/page.do?pid=112136|archivedatearchive-date=19 May 2017}}</ref> and in most fresh waters. As such it is an important sink in the [[carbon cycle]].

In [[diagnostic medicine]], the [[blood value]] of bicarbonate is one of several indicators of the state of [[acid–base physiology]] in the body. It is measured, along with [[carbon dioxide]], [[chloride]], [[potassium]], and [[sodium]], to assess [[electrolyte]] levels in an [[electrolyte panel]] test (which has [[Current Procedural Terminology]], CPT, code 80051).

The parameter ''standard bicarbonate concentration'' (SBC_e) is the bicarbonate concentration in the blood at a [[PaCO2|P_aCO₂]] of {{convert|40|mmHg|kPa|2|abbr=on}}, full oxygen saturation and 36&nbsp; °C.<ref>[http://www.nda.ox.ac.uk/wfsa/html/u13/u1312_03.htm Acid Base Balance (page 3)] {{webarchive|url=https://web.archive.org/web/20020613020114/http://www.nda.ox.ac.uk/wfsa/html/u13/u1312_03.htm |date=2002-06-13 }}</ref>

== Bicarbonate compounds ==

* [[Arterial blood gas test]]

[[Category:Bicarbonates| Bicarbonates]]