Overall P/O (ATP/O) ratio of inverted, fully coupled submitochondrial vesicles

Range for NADH 4.5: for succinate oxidation 3.0 unitless
Organism Unspecified
Reference Brand MD, Lehninger AL. H+/ATP ratio during ATP hydrolysis by mitochondria: modification of the chemiosmotic theory. Proc Natl Acad Sci U S A. 1977 May74(5):1955-9. p.1958 left column bottom paragraph & right column top paragraphPubMed ID17116
Comments "In contrast to earlier chemiosmotic models (refs 1, 38, 40), the scheme in Fig. 5 includes the energy cost of membrane translocation steps in the measured P/O ratios of 3.0 for NAD-linked and 2.0 for FAD-linked substrates. It follows that inverted, fully coupled submitochondrial vesicles, in which transport of adenine nucleotides and phosphate is unnecessary and may be inhibited without impairing ATP production, will not require protonmotive force for transport steps. The P/O ratios of such inverted vesicles should consequently be 50% greater than in intact mitochondria, i.e., the overall P/O ratio should be 4.5 for NADH and 3.0 for succinate oxidation if the chemiosmotic hypothesis is correct."
Entered by Uri M
ID 110659