Difference between revisions of "OXPHOS capacity"
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|abbr=''P'' | |abbr=''P'' | ||
|description=[[File:P.jpg]] '''OXPHOS capacity''' (''P''; compare [[State 3]]) is the respiratory capacity of mitochondria in the ADP-activated state of [[oxidative phosphorylation]], at saturating concentrations of [[ADP]], inorganic phosphate, oxygen, and defined reduced substrates. Since OXPHOS is partially coupled, intrinsic [[uncoupling]] and [[dyscoupling]] contribute to the control of flux in the OXPHOS state (State ''P''). OXPHOS capacity is expressed (i) per mt-marker (O<sub>2</sub> [[flux]] per mt-protein, [[Citrate synthase|CS]], etc); if ETS capacity, ''E'', is used as a functional mitochondrial marker, then OXPHOS capacity is expressed as the ''[[P/E]]'' ratio ([[flux control ratio]]). (ii) OXPHOS capacity is expressed per tissue or cell mass, integrating mt-quantity (density) and mt-quality (O<sub>2</sub> flux). (iii) OXPHOS capacity is expressed per cell (O<sub>2</sub> [[flow]]), which then is a function of mt-density, mt-quality, and cell size. | |description=[[File:P.jpg]] '''OXPHOS capacity''' (''P''; compare [[State 3]]) is the respiratory capacity of mitochondria in the ADP-activated state of [[oxidative phosphorylation]], at saturating concentrations of [[ADP]], inorganic phosphate, oxygen, and defined reduced substrates. Since OXPHOS is partially coupled, intrinsic [[uncoupling]] and [[dyscoupling]] contribute to the control of flux in the OXPHOS state (State ''P''). OXPHOS capacity is expressed (i) per mt-marker (O<sub>2</sub> [[flux]] per mt-protein, [[Citrate synthase|CS]], etc); if ETS capacity, ''E'', is used as a functional mitochondrial marker, then OXPHOS capacity is expressed as the ''[[P/E]]'' ratio ([[flux control ratio]]). (ii) OXPHOS capacity is expressed per tissue or cell mass, integrating mt-quantity (density) and mt-quality (O<sub>2</sub> flux). (iii) OXPHOS capacity is expressed per cell (O<sub>2</sub> [[flow]]), which then is a function of mt-density, mt-quality, and cell size. | ||
|info=[[Gnaiger | |info=[[Gnaiger 2014 MitoPathways]], [[Gnaiger 2009 Int J Biochem Cell Biol]] | ||
|type=Respiration | |type=Respiration | ||
}} | }} | ||
[[File:OXPHOS CI+II.jpg|400px|thumb|Coupled energy cycles of oxidative phosphorylation stimulated by saturating concentrations of ADP and inorganic phosphate. 2[H] indicates the reduced hydrogen equivalents of CHO substrates and electron transfer to oxygen. H<sup>+</sup><sub>out</sub> are protons pumped out of the matrix phase to the positive P-phase. Proton flow to the negative matrix phase (H<sup>+</sup><sub>in</sub>) drives the phosphorylation of ADP to ATP. The capacity of the phosphorylation system may contribute to the limitation of flux. Proton leaks dissipate energy of translocated protons from the positive P-phase to the negative N-phase. Measurement of OXPHOS capacity is possible in mt-preparations supported by an ETS-competent substrate state, exemplifed as C<sub>I+II</sub>-linked substrate supply (modified after [[Gnaiger | [[File:OXPHOS CI+II.jpg|400px|thumb|Coupled energy cycles of oxidative phosphorylation stimulated by saturating concentrations of ADP and inorganic phosphate. 2[H] indicates the reduced hydrogen equivalents of CHO substrates and electron transfer to oxygen. H<sup>+</sup><sub>out</sub> are protons pumped out of the matrix phase to the positive P-phase. Proton flow to the negative matrix phase (H<sup>+</sup><sub>in</sub>) drives the phosphorylation of ADP to ATP. The capacity of the phosphorylation system may contribute to the limitation of flux. Proton leaks dissipate energy of translocated protons from the positive P-phase to the negative N-phase. Measurement of OXPHOS capacity is possible in mt-preparations supported by an ETS-competent substrate state, exemplifed as C<sub>I+II</sub>-linked substrate supply (modified after [[Gnaiger 2014 MitoPathways]]).]] | ||
{{MitoPedia methods | {{MitoPedia methods | ||
|mitopedia method=Respirometry | |mitopedia method=Respirometry | ||
Revision as of 16:57, 26 July 2014
- high-resolution terminology - matching measurements at high-resolution
OXPHOS capacity
Description
OXPHOS capacity (P; compare State 3) is the respiratory capacity of mitochondria in the ADP-activated state of oxidative phosphorylation, at saturating concentrations of ADP, inorganic phosphate, oxygen, and defined reduced substrates. Since OXPHOS is partially coupled, intrinsic uncoupling and dyscoupling contribute to the control of flux in the OXPHOS state (State P). OXPHOS capacity is expressed (i) per mt-marker (O2 flux per mt-protein, CS, etc); if ETS capacity, E, is used as a functional mitochondrial marker, then OXPHOS capacity is expressed as the P/E ratio (flux control ratio). (ii) OXPHOS capacity is expressed per tissue or cell mass, integrating mt-quantity (density) and mt-quality (O2 flux). (iii) OXPHOS capacity is expressed per cell (O2 flow), which then is a function of mt-density, mt-quality, and cell size.
Abbreviation: P
Reference: Gnaiger 2014 MitoPathways, Gnaiger 2009 Int J Biochem Cell Biol
MitoPedia methods: Respirometry
MitoPedia topics: "Respiratory state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property.
Respiratory state"Respiratory state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property.
Related terms in Bioblast
OXPHOS, P
ETS, E
ROUTINE, R
LEAK, L
ROX, R
