Description
The R-L net ROUTINE capacity is ROUTINE respiration corrected for LEAK respiration. R-L is the respiratory capacity available for phosphorylation of ADP to ATP. Oxygen consumption in the ROUTINE state of respiration measured in living cells, therefore, is partitioned into the R-L net ROUTINE capacity, strictly coupled to phosphorylation P», and nonphosphorylating LEAK respiration, LR, compensating for proton leaks, slip and cation cycling: R = R-L+LR. It is frequently assumed that LEAK respiration L, as measured in the LEAK state, overestimates the LEAK component of respiration, LR, as measured in the ROUTINE state, particularly if the protonmotive force is not adjusted to equivalent levels in L and LR. However, if the LEAK component increases with enzyme turnover during R, the low enzyme turnover during L may counteract the effect of the higher pmF.
Abbreviation: R-L
Reference: Gnaiger 2020 BEC MitoPathways
Communicated by Gnaiger E (2014-09-21) last update 2020-11-11
Keywords
- Expand Bioblast links to R-L net ROUTINE capacity
4-compartmental OXPHOS model. (1) ET capacity E of the noncoupled electron transfer system ETS. OXPHOS capacity P is partitioned into (2) the dissipative LEAK component L, and (3) ADP-stimulated P-L net OXPHOS capacity. (4) If P-L is kinetically limited by a low capacity of the phosphorylation system to utilize the protonmotive force pmF, then the apparent E-P excess capacity is available to drive coupled processes other than phosphorylation P» (ADP to ATP) without competing with P».
- Bioblast links: Coupling control - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>
1. Mitochondrial and cellular respiratory rates in coupling-control states
Respiratory rate | Defining relations | Icon | |
---|---|---|---|
OXPHOS capacity | P = P´-Rox | mt-preparations | |
ROUTINE respiration | R = R´-Rox | living cells | |
ET capacity | E = E´-Rox | » Level flow | |
» Noncoupled respiration - Uncoupler | |||
LEAK respiration | L = L´-Rox | » Static head | |
» LEAK state with ATP | |||
» LEAK state with oligomycin | |||
» LEAK state without adenylates | |||
Residual oxygen consumption Rox | L = L´-Rox |
2. Flux control ratios related to coupling in mt-preparations and living cells
FCR | Definition | Icon | |
---|---|---|---|
L/P coupling-control ratio | L/P | » Respiratory acceptor control ratio, RCR = P/L | |
L/R coupling-control ratio | L/R | ||
L/E coupling-control ratio | L/E | » Uncoupling-control ratio, UCR = E/L (ambiguous) | |
P/E control ratio | P/E | ||
R/E control ratio | R/E | » Uncoupling-control ratio, UCR = E/L | |
net P/E control ratio | (P-L)/E | ||
net R/E control ratio | (R-L)/E |
3. Net, excess, and reserve capacities of respiration
Respiratory net rate | Definition | Icon |
---|---|---|
P-L net OXPHOS capacity | P-L | |
R-L net ROUTINE capacity | R-L | |
E-L net ET capacity | E-L | |
E-P excess capacity | E-P | |
E-R reserve capacity | E-R |
4. Flux control efficiencies related to coupling-control ratios
Coupling-control efficiency | Definition | Icon | Canonical term | ||
---|---|---|---|---|---|
P-L control efficiency | jP-L | = (P-L)/P | = 1-L/P | P-L OXPHOS-flux control efficiency | |
R-L control efficiency | jR-L | = (R-L)/R | = 1-L/R | R-L ROUTINE-flux control efficiency | |
E-L coupling efficiency | jE-L | = (E-L)/E | = 1-L/E | E-L ET-coupling efficiency » Biochemical coupling efficiency | |
E-P control efficiency | jE-P | = (E-P)/E | = 1-P/E | E-P ET-excess flux control efficiency | |
E-R control efficiency | jE-R | = (E-R)/E | = 1-R/E | E-R ET-reserve flux control efficiency |
5. General
- » Basal respiration
- » Dyscoupled respiration
- » Dyscoupling
- » Electron leak
- » Electron-transfer-pathway state
- » Hyphenation
- » Oxidative phosphorylation
- » OXPHOS analysis
- » Oxygen flow
- » Oxygen flux
- » Permeabilized cells
- » Phosphorylation system
- » Proton leak
- » Proton slip
- » Respiratory state
- » Uncoupling
MitoPedia concepts:
Respiratory state,
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