ENERGY AND REDUCTION POTENTIALS

 

DeltaG°' = - nFDeltaE°'

 

 

DeltaE°'= DeltaE°'e- acceptor- DeltaE°'e- donor

 

 

DeltaE= DeltaE° '- (RT / nF) lnQ

 

 

DeltaG = DeltaG°' + RTlnQ,

 

 

DeltaE°' = (RT / nF) lnKeq,

 

 

DeltaG°' = - RTlnKeq.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

THE ELECTRON TRANSPORT SYSTEM

 

modified from Moran & Scrimgeour Biochemistry 2nd ed. (1994) p 18.8 updated with Matti Saraste "Oxidative Phosphorylation at the fin de siécle " Science 283 (5 March 1999) pp 1488-1492.

 Complex MW Subunits Redox Components
I. NADH:ubiquinone (CoQ) oxidoreductase 900+ kD ( 'L' shaped complex) 42 or 43 subunits of unknown stoichiometry (25-26 types) 1 FMN; 7 or 8 different Fe-S centers, covalently bound lipid, 3 or more bound quinols.
II. Succinate:ubiquinone (CoQ) reductase 127 kD (anchored to membrane by b cytochrome) 4 1 FAD; 3 Fe-S clusters; 1 cytochrome b 560
 III. CoQ:cytochrome c reductase (Cytochrome bc1) 280 kD 11 (only 3 of which have redox centers and bacterial homologs)  2 cytochrome b; 1 Fe-S cluster; 1 cytochrome c 1
IV. Cytochrome c oxidase 400 kD dimer (13 chains each) 1 cytochrome a ; 1 CuA; 1 cytochrome a 3; 1 CuB; bound phospholipids

NADH right arrow [FMN right arrow Fe-S] right arrow Q right arrow [Fe-S/Cyt b right arrow Cyt c1] right arrow Cyt c right arrow [Cyt a right arrow Cyt a3] right arrow O2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NADH right arrow [FMN right arrow Fe-S] right arrow Q right arrow [Fe-S/Cyt b right arrow Cyt c1] right arrow Cyt c right arrow [Cyt a right arrow Cyt a3] right arrow O2

 

 

Electron transport system diagram

 

 

 

Succinate right arrow [FAD right arrow Fe-S] right arrow Q

Glycerol-P right arrow [FAD right arrow Fe-S] right arrow Q

Fatty acyl-CoA right arrow Fatty acyl-CoA DHsoluble right arrow [FAD right arrow Fe-S] right arrow Q

 

Last modified 12 April 2010