| 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." |