Advancement per volume: Difference between revisions
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Β Ξ<sub>r</sub>''Y'' = Ξ''c<sub>i</sub>''/''Ξ½<sub>i</sub>'' (closed system) Β | Β Ξ<sub>r</sub>''Y'' = Ξ''c<sub>i</sub>''/''Ξ½<sub>i</sub>'' (closed system) Β | ||
Ξ<sub>r</sub>''Y'' = Ξ<sub>r</sub>''c<sub>i</sub>''/''Ξ½<sub>i</sub>'' (general) | |||
In general, Ξ''c<sub>i</sub>'' is replaced by the partial change of concentration, Ξ<sub>r</sub>''c<sub>i</sub>'' (a transformation variable or process variable), which contributes to the total change of concentration, Ξ''c<sub>i</sub>'' (a system variable or variable of state). In open systems at steady-state, Ξ<sub>r</sub>''c<sub>i</sub>'' is compensated by external processes, Ξ<sub>ext</sub>''c<sub>i</sub>'' = -Ξ<sub>r</sub>''c<sub>i</sub>'', exerting an effect on the total concentration change, | |||
Ξ''c<sub>i</sub>'' = Ξ<sub>r</sub>''c<sub>i</sub>'' + Ξ<sub>ext</sub>''c<sub>i</sub>'' = 0 (steady state) | |||
Β | Β Ξ''c<sub>i</sub>'' = Ξ<sub>r</sub>''c<sub>i</sub>'' + Ξ<sub>ext</sub>''c<sub>i</sub>'' (general) | ||
|info=[[Gnaiger_1993_Pure Appl Chem |Gnaiger (1993) Pure Appl Chem]] | |info=[[Gnaiger_1993_Pure Appl Chem |Gnaiger (1993) Pure Appl Chem]] | ||
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|mitopedia method=Respirometry | |mitopedia method=Respirometry | ||
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{{MitoPedia O2k and high-resolution respirometry}} | {{MitoPedia O2k and high-resolution respirometry | ||
|mitopedia O2k and high-resolution respirometry=DatLab | |||
}} | |||
{{MitoPedia topics}} | {{MitoPedia topics}} | ||
Communicated by [[Gnaiger E]] 2018-10-19 | |||
== Application in respirometry == | == Application in respirometry == | ||
:::: In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption (''Ξ½''<sub>O2</sub> = -1 in the chemical reaction) is measured in aqueous solution, the volume-specific [[oxygen flux]] is the time derivative of the advancement of the reaction per volume [1], ''J''<sub>''V'',O2</sub> = d<sub>r</sub>''Y''<sub>O2</sub>/d''t'' = d<sub>r</sub>''ΞΎ''<sub>O2</sub>/d''t''β''V''<sup>-1</sup> [(molβsΒ<sup>-1</sup>)βLΒ<sup>-1</sup>]. The rate of O<sub>2</sub> concentration change is d''c''<sub>O2</sub>/d''t'' [(molβLΒ<sup>-1</sup>)βsΒ<sup>-1</sup>], where concentration is ''c''<sub>O2</sub> = ''n''<sub>O2</sub>β''V''<sup>-1</sup>. There is a difference between (''1'') ''J''<sub>''V'',O2</sub> [molβsΒ<sup>-1</sup>βLΒ<sup>-1</sup>] and (''2'') rate of concentration change [molβLΒ<sup>-1</sup>βsΒ<sup>-1</sup>]. These merge to a single expression only in a closed system. In open systems, internal transformations (catabolic flux, O<sub>2</sub> consumption) are distinguished from external flux (such as O<sub>2</sub> supply). External fluxes of all substances are zero in closed systems [2]. | :::: In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption (''Ξ½''<sub>O2</sub> = -1 in the chemical reaction) is measured in aqueous solution, the volume-specific [[oxygen flux]] is the time derivative of the advancement of the reaction per volume [1], ''J''<sub>''V'',O2</sub> = d<sub>r</sub>''Y''<sub>O2</sub>/d''t'' = d<sub>r</sub>''ΞΎ''<sub>O2</sub>/d''t''β''V''<sup>-1</sup> [(molβsΒ<sup>-1</sup>)βLΒ<sup>-1</sup>]. The rate of O<sub>2</sub> concentration change is d''c''<sub>O2</sub>/d''t'' [(molβLΒ<sup>-1</sup>)βsΒ<sup>-1</sup>], where concentration is ''c''<sub>O2</sub> = ''n''<sub>O2</sub>β''V''<sup>-1</sup>. There is a difference between (''1'') ''J''<sub>''V'',O2</sub> [molβsΒ<sup>-1</sup>βLΒ<sup>-1</sup>] and (''2'') rate of concentration change [molβLΒ<sup>-1</sup>βsΒ<sup>-1</sup>]. These merge to a single expression only in a closed system. In open systems, internal transformations (catabolic flux, O<sub>2</sub> consumption) are distinguished from external flux (such as O<sub>2</sub> supply). External fluxes of all substances are zero in closed systems [2]. |
Revision as of 21:22, 19 October 2018
Description
Advancement per volume or volume-specific advancement, dtrY [molβV-1], is related to advancement, dtrY = dtrΞΎβV-1, as is the amount of substance per volume, ci (concentration [molβV-1]), related to amount, ci = = niβV-1. Advancement per volume is particularly introduced for chemical reactions, drY, and has the units of concentration. In an open system at steady-state, however, the concentration does not change as the reaction advances. Only in closed systems, specific advancement equals the change in concentration divided by the stoichiometric number,
ΞrY = Ξci/Ξ½i (closed system)
ΞrY = Ξrci/Ξ½i (general)
In general, Ξci is replaced by the partial change of concentration, Ξrci (a transformation variable or process variable), which contributes to the total change of concentration, Ξci (a system variable or variable of state). In open systems at steady-state, Ξrci is compensated by external processes, Ξextci = -Ξrci, exerting an effect on the total concentration change,
Ξci = Ξrci + Ξextci = 0 (steady state)
Ξci = Ξrci + Ξextci (general)
Abbreviation: dtrY
Reference: Gnaiger (1993) Pure Appl Chem
MitoPedia concepts:
Ergodynamics
MitoPedia methods:
Respirometry
MitoPedia O2k and high-resolution respirometry:
DatLab
Communicated by Gnaiger E 2018-10-19
Application in respirometry
- In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption (Ξ½O2 = -1 in the chemical reaction) is measured in aqueous solution, the volume-specific oxygen flux is the time derivative of the advancement of the reaction per volume [1], JV,O2 = drYO2/dt = drΞΎO2/dtβV-1 [(molβsΒ-1)βLΒ-1]. The rate of O2 concentration change is dcO2/dt [(molβLΒ-1)βsΒ-1], where concentration is cO2 = nO2βV-1. There is a difference between (1) JV,O2 [molβsΒ-1βLΒ-1] and (2) rate of concentration change [molβLΒ-1βsΒ-1]. These merge to a single expression only in a closed system. In open systems, internal transformations (catabolic flux, O2 consumption) are distinguished from external flux (such as O2 supply). External fluxes of all substances are zero in closed systems [2].