State 2: Difference between revisions
From Bioblast
No edit summary |
No edit summary Β |
||
(13 intermediate revisions by 3 users not shown) | |||
Line 1: | Line 1: | ||
{{MitoPedia | {{MitoPedia | ||
|abbr=ROX<sub>D</sub> | |abbr=ROX<sub>D</sub> | ||
|description=Substrate limited state of [[residual oxygen consumption]], after addition of ADP to isolated mitochondria suspended in mitochondrial respiration medium in the absence of reduced substrates (ROX<sub>D</sub>).Β Residual endogenous substrates are oxidized during a transient stimulation of oxygen flux by ADP. The peak β supported by endogenous substrates β is, therefore, a pre-steady state phenomenon preceding State 2. Subsequently oxygen flux declines to a low level (or zero) at the steady '''State 2''' ([[Chance_1955_JBC-III|Chance and Williams 1955]]). ADP concentration (D) remains high during ROX<sub>D</sub>. | |description=[[File:ROX.jpg |link=Residual oxygen consumption]] Substrate limited state of [[residual oxygen consumption]], after addition of [[ADP]] to isolated mitochondria suspended in mitochondrial respiration medium in the absence of reduced substrates (ROX<sub>D</sub>).Β Residual endogenous substrates are oxidized during a transient stimulation of oxygen flux by ADP. The peak β supported by endogenous substrates β is, therefore, a pre-steady state phenomenon preceding State 2. Subsequently oxygen flux declines to a low level (or zero) at the steady '''State 2''' ([[Chance_1955_JBC-III|Chance and Williams 1955]]). ADP concentration (D) remains high during ROX<sub>D</sub>. | ||
|info=[[Chance 1955 JBC-III]] | |info=[[Chance 1955 JBC-III]], [[Gnaiger 2020 BEC MitoPathways]] | ||
}} | }} | ||
{{MitoPedia | {{MitoPedia concepts | ||
|mitopedia | |mitopedia concept=Respiratory state, Find | ||
}} | }} | ||
{{MitoPedia topics | {{MitoPedia topics | ||
|mitopedia topic= | |mitopedia topic=EAGLE | ||
}} | }} | ||
== | Communicated by [[Gnaiger E]] 2010-12-20, edited 2016-02-21. | ||
== ROX versus LEAK: towards a concept-linked terminology of respiratory states == | |||
::: '''ROX''' | |||
:::: State 2 is equivalent to residual oxygen consumption, ROX.Β ''We have sought independent controls on whether State 2 corresponds to complete oxidation of the system. It is logical that this be so, for respiration is zero in State 2 because substrate, not phosphate acceptor, is limiting'' ([[Chance_1955_JBC-III|Chance and Williams 1955]]). | |||
::: '''Clarification''' | |||
:::: A numerical sequence of terms defining respiratory states has been introduced by Chance and Williams. The State 2 and 4 terminology, however, has become confusing and misunderstood:Β β.. the controlled respiration prior to addition of ADP, which is strictly termed βstate 2β, is functionally the same as state 4, and the latter term is usually used for both statesβ (Nicholls and Ferguson 1992). Alchemy has a tradition of using the same term for multiple meanings and different terms for the same.Β A termonological extension from integers to the fraction 3Β½ has been suggested to indicate an intermediate mitochondrial energy state somewhere between States 3 and 4. Paradoxically, a fractional numbering system (real numbers of mathematics) would suggest that ADP-activated hypoxia were intermediate between States 3.0 and 5.0, i.e. State 4.0. This state of terminology requires fundamental reconsideration for clarification, particularly for extending bioenergetics to mitochondrial respiratory physiology and OXPHOS analysis. | |||
::: '''More details''' | |||
::::Β» [[LEAK respiration]] | |||
:: | ::::Β» [[MitoPedia: Respiratory states]] | ||
Β | |||
Β | |||
Β | |||
Β | |||
Β | |||
Β | |||
Β | |||
Β | |||
Latest revision as of 18:45, 1 January 2021
Description
Substrate limited state of residual oxygen consumption, after addition of ADP to isolated mitochondria suspended in mitochondrial respiration medium in the absence of reduced substrates (ROXD). Residual endogenous substrates are oxidized during a transient stimulation of oxygen flux by ADP. The peak β supported by endogenous substrates β is, therefore, a pre-steady state phenomenon preceding State 2. Subsequently oxygen flux declines to a low level (or zero) at the steady State 2 (Chance and Williams 1955). ADP concentration (D) remains high during ROXD.
Abbreviation: ROXD
Reference: Chance 1955 JBC-III, Gnaiger 2020 BEC MitoPathways
MitoPedia concepts:
Respiratory state,
Find
MitoPedia topics:
EAGLE
Communicated by Gnaiger E 2010-12-20, edited 2016-02-21.
ROX versus LEAK: towards a concept-linked terminology of respiratory states
- ROX
- State 2 is equivalent to residual oxygen consumption, ROX. We have sought independent controls on whether State 2 corresponds to complete oxidation of the system. It is logical that this be so, for respiration is zero in State 2 because substrate, not phosphate acceptor, is limiting (Chance and Williams 1955).
- ROX
- Clarification
- A numerical sequence of terms defining respiratory states has been introduced by Chance and Williams. The State 2 and 4 terminology, however, has become confusing and misunderstood: β.. the controlled respiration prior to addition of ADP, which is strictly termed βstate 2β, is functionally the same as state 4, and the latter term is usually used for both statesβ (Nicholls and Ferguson 1992). Alchemy has a tradition of using the same term for multiple meanings and different terms for the same. A termonological extension from integers to the fraction 3Β½ has been suggested to indicate an intermediate mitochondrial energy state somewhere between States 3 and 4. Paradoxically, a fractional numbering system (real numbers of mathematics) would suggest that ADP-activated hypoxia were intermediate between States 3.0 and 5.0, i.e. State 4.0. This state of terminology requires fundamental reconsideration for clarification, particularly for extending bioenergetics to mitochondrial respiratory physiology and OXPHOS analysis.
- Clarification
- More details