Microbes and Metabolism - Environmental Biotechnology: Theory and Application - page 31

Figure2.8 Fermentations
Lehninger (1975) the gist of which is outlined in this section. The details of
exactly how these phenomena combine to drive the synthesis of ATP is still
unclear but various models have been proposed.
The chemiosmotic model, proposed by Peter Mitchell in 1961, states that the
proton, or hydrogen ion, gradient which develops across an intact membrane
during biological oxidations is the energy store for the subsequent synthesis
of ATP. This model somewhat revolutionised the then current thinking on the
energy source for many cellular processes, as the principles of energy storage
and availability according to the chemiosmotic theory were applicable to many
energy demanding cellular phenomena including photosynthetic phosphorylation
and some cross-membrane transport systems. It could even account for the move-
ment of flagellae which propel those bacteria possessing them, through a liquid
medium. The chemiosmotic theory accounts for the coupling of the transmem-
brane proton gradient to ATP synthesis. It implies that during oxidation, the