Rate of glucose-induced proton efflux

Value 0.687 nmol of H+/min/mg yeast Range: ±0.077 nmol of H+/min/mg yeast
Organism Budding yeast Saccharomyces cerevisiae
Reference Holyoak et al. Activity of the plasma membrane H(+)-ATPase and optimal glycolytic flux are required for rapid adaptation and growth of Saccharomyces cerevisiae in the presence of the weak-acid preservative sorbic acid. 1996. Appl Environ Microbiol. 62(9): p.3162.PubMed ID8795204
Method determined from the rate of proton extrusion into unbuffered water.
Comments at pH 5.7 in late-exponential phase growth at 30 degrees C. This proton flux is primarily, if not completely through the plasma membrane H+ ATPase. Approximating the mass of 1 cell as 60pg, there are about 17 million yeast cells in 1 mg. The calculation 0.687nmol*6.02E23/17 million gives a value of about 24 million H+ per cell per min, or 400,000 H+ per cell per second.
Entered by Phil Mongiovi
ID 101902