Difference between revisions of "Pathway control ratio"
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|description='''Substrate control ratios''', ''SCR'', are [[flux control ratio]]s, ''FCR'', at a constant mitochondrial [[coupling state]]. Whereas there are only three well-defined coupling states of mitochondrial respiration, ''L'', ''P'', ''E'' ([[LEAK]], [[OXPHOS]], [[ETS]]), numerous [[substrate state]]s are possible. Β | |description='''Substrate control ratios''', ''SCR'', are [[flux control ratio]]s, ''FCR'', at a constant mitochondrial [[coupling state]]. Whereas there are only three well-defined coupling states of mitochondrial respiration, ''L'', ''P'', ''E'' ([[LEAK]], [[OXPHOS]], [[ETS]]), numerous [[substrate state]]s are possible. Β | ||
Careful selection of the reference state, ''J''<sub>ref</sub>, is required, for which some guidelines may be provided without the possibility to formulate general rules. ''FCR'' are best defined by taking ''J''<sub>ref</sub> as the maximum flux (e.g. [[Additive effect of convergent CI+II electron flow| | Careful selection of the reference state, ''J''<sub>ref</sub>, is required, for which some guidelines may be provided without the possibility to formulate general rules. ''FCR'' are best defined by taking ''J''<sub>ref</sub> as the maximum flux (e.g. [[Additive effect of convergent CI+II electron flow|CI<small>&</small>II]]<sub>''[[ETS|E]]''</sub>), such that flux in various other respiratory states, ''J<sub>i</sub>'', smaller or equal to ''J''<sub>ref</sub>. However, this is not generally possible with ''SCR''. For instance, the CI/CII substrate control ratio (at constant coupling state) may be larger or smaller than 1.0, depending on the mitochondrial source and various mitochondrial injuries. CII-linked respiration may be selected preferentially as ''J''<sub>ref</sub>, if mitochondria with variable CI-linked injuries are studied. In contrast, the [[reference state]], ''Z'', is strictly defined for [[flux control factor]]s. | ||
|info=[[Gnaiger 2009 Int J Biochem Cell Biol]]; [[ | |info=[[Gnaiger 2009 Int J Biochem Cell Biol]]; [[Bioblast Glossary: Respiratory states]] | ||
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{{MitoPedia methods | {{MitoPedia methods |
Revision as of 20:47, 31 August 2014
Description
Substrate control ratios, SCR, are flux control ratios, FCR, at a constant mitochondrial coupling state. Whereas there are only three well-defined coupling states of mitochondrial respiration, L, P, E (LEAK, OXPHOS, ETS), numerous substrate states are possible.
Careful selection of the reference state, Jref, is required, for which some guidelines may be provided without the possibility to formulate general rules. FCR are best defined by taking Jref as the maximum flux (e.g. CI&IIE), such that flux in various other respiratory states, Ji, smaller or equal to Jref. However, this is not generally possible with SCR. For instance, the CI/CII substrate control ratio (at constant coupling state) may be larger or smaller than 1.0, depending on the mitochondrial source and various mitochondrial injuries. CII-linked respiration may be selected preferentially as Jref, if mitochondria with variable CI-linked injuries are studied. In contrast, the reference state, Z, is strictly defined for flux control factors.
Abbreviation: SCR
Reference: Gnaiger 2009 Int J Biochem Cell Biol; Bioblast Glossary: Respiratory states
MitoPedia methods:
Respirometry
MitoPedia topics: "Respiratory control ratio" 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 control ratio"Respiratory control ratio" 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.