TABLE 5.

Calculations of the stoichiometry of complex I using published P/O ratios

The stoichiometry of complex I was calculated using the single data set chosen by Wikström and Hummer (45, 46), using all of the values collated by Hinkle in 2005 (9), and using all of the values reported from 1975 onwards collated by Hinkle. For the single study (46), the errors are the experimental errors reported from that study. For the values collated by Hinkle, the standard deviations describe the variation between studies. The final stoichiometry values have been calculated using 1.5 for the known P/O ratio of complexes III + IV.

Reactions considered	Complexes that contribute to Δp	Single data set	All studies	Studies from 1975
P/O ratios
Reaction A	I + III + IV	2.27 ± 0.08	2.47 ± 0.45	2.64 ± 0.36
Reaction B	III + IV	1.48 ± 0.04	1.56 ± 0.17	1.56 ± 0.17
Reaction C	III	0.49 ± 0.02	0.58 ± 0.21	0.48 ± 0.03
Reaction D	IV	0.98 ± 0.09	1.03 ± 0.15	1.09 ± 0.18
A − B	I	0.79 ± 0.09	0.92 ± 0.48	1.08 ± 0.39
A − (C + D)	I	0.80 ± 0.12	0.86 ± 0.51	1.07 ± 0.40
Complex I H+/2 e−stoichiometries
A − B	I	2.90 ± 0.33	3.36 ± 1.75	3.97 ± 1.45
A − (C + D)	I	2.93 ± 0.45	3.15 ± 1.86	3.93 ± 1.47
A − 1.5	I	2.82 ± 0.29	3.57 ± 1.63	4.20 ± 1.31