Two protons are pumped from the mitochondrial matrix per electron transferred between NADH and ubiquinone.
The spectrophotometric indicators neutral red and safranine were used to determine the relative H+/e- ratios of proton uptake from the mitochondrial matrix, and the q+/e- ratios of electrical charge translocation, during oxidation of beta-OH-butyrate and succinate by ferricyanide in rat liver mitochondria. With beta-OH-butyrate both ratios were higher than with succinate by a factor close to 3.0. Since there is full agreement that H+/e- of proton uptake and q+/e- of charge translocation are both equal to unity for oxidation of succinate (or ubiquinol) by ferricytochrome c, the corresponding ratios for oxidation of NADH by ubiquinone and cytochrome c are near 2.0 and 3.0, respectively.
D000818:Animals; D006885:Hydroxybutyrates / Q000378:metabolism; D007202:Indicators and Reagents; D008930:Mitochondria, Liver / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D009499:Neutral Red; D010084:Oxidation-Reduction; D010619:Phenazines; D011522:Protons; D051381:Rats; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid; D014451:Ubiquinone / Q000378:metabolism*
D006885:Hydroxybutyrates; D007202:Indicators and Reagents; D010619:Phenazines; D011522:Protons; D013386:Succinates; D009243:NAD; D014451:Ubiquinone; D009499:Neutral Red; D019802:Succinic Acid; C009195:safranine T