P/O ratio (ATP made per O atom reduced)

Range non-energy linked activity of NADH dehydrogenase (ndh) 0.667: energy linked activity of ndh 1.33 unitless
Organism Bacteria Escherichia coli
Reference Varma, Amit, Palsson, Bernhard O. (1993/12/21)."Metabolic Capabilities of Escherichia coli II. Optimal Growth Patterns." Journal of Theoretical Biology 165(4): 503-522. <http://hdl.handle.net/2027.42/30387> link pdf link p.512 4th paragraph
Primary Source Poole RK, Haddock BA. Energy-linked reduction of nicotinamideadenine dinucleotide in membranes derived from normal and various respiratory-deficient mutant strains of Escherichia coli K12. Biochem J. 1974 Oct144(1):77-85.PubMed ID4156832
Comments P.512 4th paragraph: "The enzyme NADH dehydrogenase (ndh) transfers hydrogen from NADH to quinone. Both energy-linked and unlinked activities have been observed (primary source). Use of the non-energy linked activity results in a P/O ratio of 0.667 as compared to a P/O ratio of 1.33 for energy linked dehydrogenase, assuming an ATPase stoichiometry of 3H+/ATP. Figure 4(a) depicts the maximal biomass yield with either of the NADH dehydrogenases. The use of the non-energy linked NADH dehydrogenase, i.e. reducing the P/O ratio by 50%, results in a significant drop in the biomass yield, to 0.519g DW/g glucose, a drop of 11.7%."
Entered by Uri M
ID 113250