Editing Oxidative phosphorylation (section)

=== Organization of complexes ===
The original model for how the respiratory chain complexes are organized was that they diffuse freely and independently in the mitochondrial membrane.<ref name=Lenaz2001>{{cite journal | vauthors = Lenaz G | title = A critical appraisal of the mitochondrial coenzyme Q pool | journal = FEBS Letters | volume = 509 | issue = 2 | pages = 151–155 | date = December 2001 | pmid = 11741580 | doi = 10.1016/S0014-5793(01)03172-6 | s2cid = 46138989 | doi-access = free | bibcode = 2001FEBSL.509..151L }}</ref> However, recent data suggest that the complexes might form higher-order structures called supercomplexes or "[[respirasome]]s".<ref>{{cite journal | vauthors = Heinemeyer J, Braun HP, Boekema EJ, Kouril R | title = A structural model of the cytochrome C reductase/oxidase supercomplex from yeast mitochondria | journal = The Journal of Biological Chemistry | volume = 282 | issue = 16 | pages = 12240–12248 | date = April 2007 | pmid = 17322303 | doi = 10.1074/jbc.M610545200 | s2cid = 18123642 | doi-access = free }}</ref> In this model, the various complexes exist as organized sets of interacting enzymes.<ref>{{cite journal | vauthors = Schägger H, Pfeiffer K | title = Supercomplexes in the respiratory chains of yeast and mammalian mitochondria | journal = The EMBO Journal | volume = 19 | issue = 8 | pages = 1777–1783 | date = April 2000 | pmid = 10775262 | pmc = 302020 | doi = 10.1093/emboj/19.8.1777 }}</ref> These associations might allow channeling of substrates between the various enzyme complexes, increasing the rate and efficiency of electron transfer.<ref>{{cite journal | vauthors = Schägger H | title = Respiratory chain supercomplexes of mitochondria and bacteria | journal = Biochimica et Biophysica Acta (BBA) - Bioenergetics | volume = 1555 | issue = 1–3 | pages = 154–159 | date = September 2002 | pmid = 12206908 | doi = 10.1016/S0005-2728(02)00271-2 | doi-access = free }}</ref> Within such mammalian supercomplexes, some components would be present in higher amounts than others, with some data suggesting a ratio between complexes I/II/III/IV and the ATP synthase of approximately 1:1:3:7:4.<ref>{{cite journal | vauthors = Schägger H, Pfeiffer K | title = The ratio of oxidative phosphorylation complexes I-V in bovine heart mitochondria and the composition of respiratory chain supercomplexes | journal = The Journal of Biological Chemistry | volume = 276 | issue = 41 | pages = 37861–37867 | date = October 2001 | pmid = 11483615 | doi = 10.1074/jbc.M106474200 | url = http://www.jbc.org/cgi/content/full/276/41/37861 | url-status = live | doi-access = free | archive-url = https://web.archive.org/web/20070929115026/http://www.jbc.org/cgi/content/full/276/41/37861 | archive-date = 2007-09-29 }}</ref> However, the debate over this supercomplex hypothesis is not completely resolved, as some data do not appear to fit with this model.<ref name=Lenaz2006/><ref>{{cite journal | vauthors = Gupte S, Wu ES, Hoechli L, Hoechli M, Jacobson K, Sowers AE, Hackenbrock CR | title = Relationship between lateral diffusion, collision frequency, and electron transfer of mitochondrial inner membrane oxidation-reduction components | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 81 | issue = 9 | pages = 2606–2610 | date = May 1984 | pmid = 6326133 | pmc = 345118 | doi = 10.1073/pnas.81.9.2606 | doi-access = free | bibcode = 1984PNAS...81.2606G }}</ref>