Respiratory states of mitochondrial preparations and intact cells are defined in the current literature in many ways and with a diversity of terms. Mitochondrial respiratory states must be defined in terms of both, the coupling control state and the electron transfer-pathway state.
Reference: Gnaiger 2014 MitoPathways
MitoPedia topics: EAGLE
Communicated by Gnaiger E 2010-10-21, edited 2016-08-26.
Coupling control states
- Coupling states and CCR of mitochondrial preparations:
- Coupling states of intact cells:
Electron transfer-pathway state
- Electron transfer-pathway state, PCS, are defined by substrate type (at saturating concentration):
- Intact cells: endogenous, exogenous substrate control
- Mitochondrial preparations: specific substrate-inhibitor combinations for selectively stimulating electron entry though Complex I, CII, or other branches converging at the Q-junction, particularly with fatty acid oxidation, alpha-glycerophosphate, (Complex I-linked substrate state, Complex II-linked substrate state, etc.), or substrate combinations applied for reconstitution of TCA cycle function (e.g. Complex I&II-linked substrate state, etc.).
- Control by substrate concentration: Kinetic control states:
- Kinetic substrate or adenylate control: Kinetic studies with variation of a specific substrate (reduced substrate supplying electrons to the ETS; ADP, Pi; O2; cytochrome c) are analyzed by kinetic functions (e.g. hyperbolic), yielding apparent kinetic constants, such as Jmax, Km', c50, or p50.
- Kinetic inhibitor control: Kinetic studies with variation of a specific inhibitor yield apparent kinetic constants, such as the KI'.
Classical respiratory states
- Chance and Williams (1955):
- Derived respiratory states:
- Thermodynamics of irreversible processes: