Editing Mitochondrial matrix (section)

== Composition ==

=== Metabolites ===
The matrix is host to a wide variety of [[metabolite]]s involved in processes within the matrix. The [[citric acid cycle]] involves [[acyl-CoA]], [[pyruvate]], [[acetyl-CoA]], [[citrate]], [[isocitrate]], [[α-ketoglutarate]], [[succinyl-CoA]], [[fumarate]], [[succinate]], [[malate|<small>L</small>-malate]], and [[oxaloacetate]].<ref name=":1" /> The [[urea cycle]] makes use of [[ornithine|<small>L</small>-ornithine]], [[Carbamoyl phosphate synthetase I|carbamoyl phosphate]], and [[L-citrulline|<small>L</small>-citrulline]].<ref name=":5" /> The electron transport chain oxidizes coenzymes [[NADH]] and [[FADH2]]. Protein synthesis makes use of mitochondrial [[DNA]], [[RNA]], and [[Transfer RNA|tRNA]].<ref name=":6" /> Regulation of processes makes use of ions ([[Ca2+|Ca<sup>2+</sup>]]/[[Potassium|K<sup>+</sup>]]/[[Magnesium|Mg<sup>+</sup>]]).<ref name=":4" /> Additional metabolites present in the matrix are [[CO2|CO<sub>2</sub>]]<sub>,</sub> [[H2O|H<sub>2</sub>O]], [[Oxygen|O<sub>2</sub>]]<sub>,</sub> [[Adenosine triphosphate|ATP]], [[Adenosine diphosphate|ADP]], and [[Inorganic phosphate|P<sub>i</sub>]].<ref name=":0" />

=== Enzymes ===
Enzymes from processes that take place in the matrix. The citric acid cycle is facilitated by [[pyruvate dehydrogenase]], [[citrate synthase]], [[aconitase]], [[isocitrate dehydrogenase]], [[α-ketoglutarate dehydrogenase]], [[succinyl coenzyme A synthetase|succinyl-CoA synthetase]], [[fumarase]], and [[malate dehydrogenase]].<ref name=":1" /> The urea cycle is facilitated by [[carbamoyl phosphate synthetase I]] and [[ornithine transcarbamylase]].<ref name=":5" /> β-Oxidation uses [[pyruvate carboxylase]], [[Acyl CoA dehydrogenase|acyl-CoA dehydrogenase]], and [[β-ketothiolase]].<ref name=":0" /> Amino acid production is facilitated by [[transaminase]]s.<ref name=":7" /> Amino acid metabolism is mediated by [[protease]]s, such as [[PITRM1|presequence protease]].<ref>{{Cite journal|last1=King|first1=John V.|last2=Liang|first2=Wenguang G.|last3=Scherpelz|first3=Kathryn P.|last4=Schilling|first4=Alexander B.|last5=Meredith|first5=Stephen C.|last6=Tang|first6=Wei-Jen|date=2014-07-08|title=Molecular basis of substrate recognition and degradation by human presequence protease|journal=Structure|volume=22|issue=7|pages=996–1007|doi=10.1016/j.str.2014.05.003|issn=1878-4186|pmc=4128088|pmid=24931469}}</ref>

=== Inner membrane components ===
The inner membrane is a [[phospholipid bilayer]] that contains the complexes of oxidative phosphorylation. which contains the [[electron transport chain]] that is found on the [[crista]]e of the inner membrane and consists of four protein complexes and [[ATP synthase]]. These complexes are [[complex I]] (NADH:coenzyme Q oxidoreductase), [[complex II]] (succinate:coenzyme Q oxidoreductase), [[complex III]] (coenzyme Q: cytochrome c oxidoreductase), and [[complex IV]] (cytochrome c oxidase).<ref name=":4" />

=== Inner membrane control over matrix composition ===
The electron transport chain is responsible for establishing a pH and [[electrochemical gradient]] that facilitates the production of ATP through the pumping of protons. The gradient also provides control of the concentration of ions such as [[Ca2|Ca<sup>2+</sup>]] driven by the mitochondrial membrane potential.<ref name=":0" /> The membrane only allows nonpolar molecules such as [[Carbon dioxide|CO<sub>2</sub>]] and [[Oxygen|O<sub>2</sub>]] and small non charged polar molecules such as [[H2O|H<sub>2</sub>O]] to enter the matrix. Molecules enter and exit the mitochondrial matrix through [[transport protein]]s and [[ion transporter]]s. Molecules are then able to leave the mitochondria through [[Porin (protein)|porin]].<ref name=":2">{{Cite book|title=Molecular Biology of the Cell|last1=Alberts|first1=Bruce|last2=Johnson|first2=Alexander|last3=Lewis|first3=julian|last4=Roberts|first4=Keith|last5=Peters|first5=Walter|last6=Raff|first6=Martin|publisher=Garland Publishing Inc|year=1994|isbn=978-0-8153-3218-3|location=New york}}</ref> These attributed characteristics allow for control over concentrations of [[ion]]s and [[metabolite]]s necessary for regulation and determines the rate of ATP production.<ref>{{Cite journal|last1=Anderson|first1=S.|last2=Bankier|first2=A. T.|last3=Barrell|first3=B. G.|last4=de Bruijn|first4=M. H. L.|last5=Coulson|first5=A. R.|last6=Drouin|first6=J.|last7=Eperon|first7=I. C.|last8=Nierlich|first8=D. P.|last9=Roe|first9=B. A.|date=1981-04-09|title=Sequence and organization of the human mitochondrial genome|journal=Nature|language=en|volume=290|issue=5806|pages=457–465|doi=10.1038/290457a0|pmid=7219534|bibcode=1981Natur.290..457A |s2cid=4355527 }}</ref><ref name=":3">{{Cite journal|last1=Iuchi|first1=S.|last2=Lin|first2=E. C. C.|date=1993-07-01|title=Adaptation of Escherichia coli to redox environments by gene expression|journal=Molecular Microbiology|language=en|volume=9|issue=1|pages=9–15|doi=10.1111/j.1365-2958.1993.tb01664.x|issn=1365-2958|pmid=8412675|s2cid=39165641 }}</ref>