Standard
Reduction Potentials (E0'), 25oC
|
oxidant
|
reductant
|
n (electrons)
|
Eo´ (volts)
|
|
Acetate + carbon dioxide
|
pyruvate
|
2
|
-0.70
|
|
succinate + CO2 + 2H+
|
a-ketoglutarate + H2O
|
2
|
-0.67
|
|
acetate
|
acetaldehyde
|
2
|
-0.60
|
|
glycerate-3-P
|
glyceraldehyde-3-P + H2O
|
2
|
-0.55
|
|
O2
|
O2-
|
1
|
-0.45
|
|
ferredoxin (ox)
|
ferredoxin (red)
|
1
|
-0.43
|
|
Carbon dioxide
|
formate
|
2
|
-0.42
|
|
2H+
|
H2
|
2
|
-0.42
|
|
a-ketoglutarate + CO2 + 2H+
|
isocitrate
|
2
|
-0.38
|
|
acetoacetate
|
b-hydroxybutyrate
|
2
|
-0.35
|
|
Cystine
|
cysteine
|
2
|
-0.34
|
|
Pyruvate + CO2
|
malate
|
2
|
-0.33
|
|
NAD+ + 2H+
|
NADH +
H+
|
2
|
-0.32
|
|
NADP+ + 2H+
|
NADPH +
H+
|
2
|
-0.32
|
|
FMN (enzyme bound)
|
FMNH2
|
2
|
-0.30
|
|
Lipoic acid, ox
|
Lipoic acid,
red
|
2
|
-0.29
|
|
1,3 bisphosphoglycerate + 2H+
|
glyceraldehyde-3-P
+ Pi
|
2
|
-0.29
|
|
Glutathione, ox
|
red
|
2
|
-0.23
|
|
FAD (free) + 2H+
|
FADH2
|
2
|
-0.22
|
|
Acetaldehyde + 2H+
|
ethanol
|
2
|
-0.20
|
|
Pyruvate + 2H+
|
lactate
|
2
|
-0.19
|
|
Oxalacetate + 2H+
|
malate
|
2
|
-0.17
|
|
a-ketoglutarate + NH4+
|
glutamate
|
2
|
-0.14
|
|
FAD + 2H+ (bound)
|
FADH2 (bound)
|
2
|
0.003-0.09
|
|
Methylene blue, ox
|
Methylene
blue, red
|
2
|
0.01
|
|
Fumarate + 2H+
|
succinate
|
2
|
0.03
|
|
CoQ (Ubiquinone - UQ + H+
|
UQH.
|
1
|
0.031
|
|
UQ + 2H+
|
UQH2
|
2
|
0.06
|
|
Dehydroascorbic acid
|
ascorbic acid
|
2
|
0.06
|
|
Ubiquinone; ox
|
red
|
2
|
0.10
|
|
Cytochrome b2; Fe3+
|
Cytochrome b2; Fe2+
|
1
|
0.12
|
|
Cytochrome c1; Fe3+
|
Cytochrome c1; Fe2+
|
1
|
0.22
|
|
Cytochrome c; Fe3+
|
Cytochrome c;
Fe2+
|
1
|
0.25
|
|
Cytochrome a; Fe3+
|
Cytochrome a;
Fe2+
|
1
|
0.29
|
|
1/2 O2 + H2O
|
H2O2
|
2
|
0.30
|
|
Cytochrome a3; Fe3+
|
Cytochrome a3;
Fe2+
|
1
|
0.35
|
|
Ferricyanide
|
ferrocyanide
|
2
|
0.36
|
|
Cytochrome f; Fe3+
|
Cytochrome f;
Fe2+
|
1
|
0.37
|
|
Nitrate
|
nitrite
|
1
|
0.42
|
|
Photosystem P700
|
.
|
.
|
0.43
|
|
Fe3+
|
Fe2+
|
1
|
0.77
|
|
1/2 O2 + 2H+
|
H2O
|
2
|
0.816
|
