Respiratory enzymes and substrates in eukaryotes.
Respiratory enzyme
complex		 Complex Redox Component  Redox potential 

(Volts)
 NADH dehydrogenase NAD+ / NADH −0.32
 Succinate dehydrogenase FMN or FAD / FMNH2 or FADH2 −0.20
 Cytochrome bc1 complex Coenzyme Q10ox / Coenzyme Q10red +0.06
 Cytochrome bc1 complex Cytochrome box / Cytochrome bred +0.12
 Complex IV Cytochrome cox / Cytochrome cred +0.22
 Complex IV Cytochrome aox / Cytochrome ared +0.29
 Complex IV O2 / HO- +0.82[1]

       [1] Medical CHEMISTRY Compendium. By Anders Overgaard Pedersen and Henning Nielsen. Aarhus University. 2008