Editing Glycolysis (section)

== Overview ==
The overall reaction of glycolysis is:
<div style="display:flex; flex-flow:row wrap; border:1px solid #a79c83; margin:1em">
{{Biochem reaction subunit|compound={{sm|d}}-Glucose|link=Glucose|image=D-glucose wpmp.svg|class=skin-invert-image}}
{{Biochem reaction subunit|title=&nbsp;|style=background:light-dark(lightgreen,darkgreen)|other_content=+&nbsp;2&nbsp;[NAD]<sup>+</sup><br />+&nbsp;2&nbsp;[ADP]<br />+&nbsp;2&nbsp;[P]<sub>i</sub>}}
{{Biochem reaction subunit|title=&nbsp;|enzyme=various}}
{{Biochem reaction subunit|n=2|compound=Pyruvate|image=Pyruvate skeletal.svg|class=skin-invert-image}}
{{Biochem reaction subunit|title=&nbsp;|style=background:light-dark(lightgreen,darkgreen)|other_content=+&nbsp;2&nbsp;[NADH]<br />+&nbsp;2&nbsp;H<sup>+</sup><br />+&nbsp;2&nbsp;[ATP]<br />+&nbsp;2&nbsp;H<sub>2</sub>O}}</div>
[[File:Glycolysis.svg|thumb|445x445px|class=skin-invert-image|Glycolysis pathway overview]]
The use of symbols in this equation makes it appear unbalanced with respect to oxygen atoms, hydrogen atoms, and charges. Atom balance is maintained by the two phosphate (P<sub>i</sub>) groups:<ref name="ImportanceBalance">{{Cite journal| vauthors = Lane AN, Fan TW, Higashi RM | title = Metabolic acidosis and the importance of balanced equations | journal = Metabolomics| volume = 5| issue = 2| pages = 163–165| year = 2009| doi = 10.1007/s11306-008-0142-2 | s2cid = 35500999}}</ref>
* Each exists in the form of a [[Phosphoric acid#Orthophosphoric acid chemistry|hydrogen phosphate]] anion ({{chem2|[HPO4](2−)}}), dissociating to contribute {{chem2|2H+}} overall
* Each liberates an oxygen atom when it binds to an [[adenosine diphosphate]] (ADP) molecule, contributing 2{{nbsp}}O overall

Charges are balanced by the difference between ADP and ATP.  In the cellular environment, all three hydroxyl groups of ADP dissociate into −O<sup>−</sup> and H<sup>+</sup>, giving ADP<sup>3−</sup>, and this ion tends to exist in an ionic bond with Mg<sup>2+</sup>, giving ADPMg<sup>−</sup>.  ATP behaves identically except that it has four hydroxyl groups, giving ATPMg<sup>2−</sup>.  When these differences along with the true charges on the two phosphate groups are considered together, the net charges of −4 on each side are balanced.{{cn|date=September 2024}}

In high-oxygen (aerobic) conditions, eukaryotic cells can continue from glycolysis to metabolise the pyruvate through the [[citric acid cycle]]  or the [[electron transport chain]] to produce significantly more ATP.
 
Importantly, under low-oxygen (anaerobic) conditions, glycolysis is the only biochemical pathway in eukaryotes that can generate ATP, and, for many anaerobic respiring organisms the most important producer of ATP.<ref>{{cite book |display-authors=Alberts et al. |title=Molecular Biology of the Cell |date=18 November 2014 |publisher=Garland Science |isbn= 978-0815344322  |pages=75 |edition=6th}}</ref> Therefore, many organisms have evolved [[fermentation (biochemistry)|fermentation]] pathways to recycle NAD<sup>+</sup> to continue glycolysis to produce ATP for survival. These pathways include [[ethanol fermentation]] and [[lactic acid fermentation]].

{| class="toccolours collapsible collapsed" width="100%" style="text-align:left"
! Metabolism of common [[monosaccharide]]s, including glycolysis, [[gluconeogenesis]], [[glycogenesis]] and [[glycogenolysis]]
|-
| [[File:Metabolism of common monosaccharides, and related reactions.png|none|1000px|class=skin-invert-image]]
|}