The fermentation of sugar by cell-free yeast extracts was demonstrated
more than a century ago by E. Buchner (Nobel Prize 1907). Buchner's
observations put an end to previous animistic theories regarding
cellular life. It became clear that metabolism and all cellular
functions should be accessible to explication in chemical terms. Equally
important for an understanding of living systems was the concept,
explained in physical terms, that all living things could be cons- ered
as energy converters [E. Schrödinger (Nobel Prize 1933)] which
generate complexity at the expense of an increase in entropy in their
environment. Bioenergetics was established as an essential branch of the
biochemical sciences by the investigations into the chemistry of
photosynthesis in i- lated plant organelles [O. Warburg (Nobel Prize
1931)] and by the discovery that mitochondria were the morphological
equivalent that catalyzed cellular respiration. The ?eld of
bioenergetics also encompasses a large variety of ad- tional processes
such as the molecular mechanisms of muscle contraction, the structure
and driving mechanisms of microbial ?agellar motors, the energetics of
solute transport, the extrusion of macromolecules across membranes, the
transformation of quanta of light into visual information and the
maintenance of complex synaptic communications. There are many other
examples which, in most cases, may perform secondary energy
transformations, utilizing - ergy stored either in the cellular ATP pool
or in electrochemical membrane potentials.
