Template:SUIT-004

Steps and respiratory states

Step	State	Pathway	Q-junction	Comment - Events (E) and Marks (M)
1PM	PM_L	N	CI	PM_L or PM_L: Pyruvate & malate, N-LEAK respiration, N_L NADH-linked substrates (type N-pathway to Q). Template:SUIT L n
2D	PM_P	N	CI	1PM;2D NADH-linked substrates (type N-pathway to Q). OXPHOS capacity P (with saturating [ADP]), active OXPHOS state.
2c	PMc_P	N	CI	1PM;2D;2c NADH-linked substrates (type N-pathway to Q). OXPHOS capacity P (with saturating [ADP]), active OXPHOS state. Addition of cytochrome c yields a test for integrity of the mtOM (cytochrome c control efficiency). Stimulation by added cytochrome c would indicate an injury of the mtOM and limitation of respiration in the preceding state without added c due to loss of cytochrome c. Typically, cytochrome c is added immediately after the earliest ADP-activation step (OXPHOS capacity P with saturating [ADP]).
3U	PM_E	NS	CI&II	1PM;2D;3U Respiratory stimulation by simultaneous action of type N substrates & succinate, with convergent electron flow in the NS-pathway for reconstitution of TCA cycle function. Uncoupler titration (avoiding inhibition by high uncoupler concentrations) to obtain electron transfer (ET) capacity E (noncoupled ET-state). Test for limitation of OXPHOS capacity P by the phosphorylation system (ANT, ATP synthase, phosphate transporter) relative to ET capacity E in mt-preparations: E-P control efficiency and E-L coupling efficiency. In living cells: E-R control efficiency and E-L coupling efficiency.
4S	PMS_E	NS	CI&II	1PM;2D;3U;4S NADH-linked substrates (type N-pathway to Q). & Succinate, S ( type S-pathway to Q). Respiratory stimulation by simultaneous action of type N substrates & succinate, with convergent electron flow in the NS-pathway for reconstitution of TCA cycle function. OXPHOS capacity P (with saturating [ADP]), active OXPHOS state.
5Rot	S_E	S	CII	1PM;2D;3U;4S;5Rot Succinate pathway control state (S-pathway) after inhibiting CI with rotenone, which also inhibits the F-pathway. Noncoupled electron transfer state, ET state, with ET capacity E.
6Ama	ROX			1PM;2D;3U;4S;5Rot;6Ama Rox is the residual oxygen consumption in the ROX state, due to oxidative side reactions, estimated after addition of antimycin A (inhibitor of CIII). Rox is subtracted from oxygen flux as a baseline for all respiratory states, to obtain mitochondrial respiration (mt).

Step	Respiratory state	Pathway control	ET-Complex	Comment
## AsTm	AsTm_E	CIV	CIV
## Azd	CHB