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Efficiency of energy conversion in model biological pumps. Optimization by linear nonequilibrium thermodynamic relations.

Efficiency of energy conversion in model biological pumps. Optimization by linear nonequilibrium thermodynamic relations.

Authors :
Stucki JW
Compiani M
Caplan SR
Source :
Biophysical chemistry [Biophys Chem] 1983 Sep; Vol. 18 (2), pp. 101-9.
Publication Year :
1983

Abstract

Experimental investigations showed linear relations between flows and forces in some biological energy converters operating far from equilibrium. This observation cannot be understood on the basis of conventional nonequilibrium thermodynamics. Therefore, the efficiencies of a linear and a nonlinear mode of operation of an energy converter (a hypothetical redox-driven H+ pump) were compared. This comparison revealed that at physiological values of the forces and degrees of coupling (1) the force ratio permitting optimal efficiency was much higher in the linear than in the nonlinear mode and (2) the linear mode of operation was at least 10(6)-times more efficient that the nonlinear one. These observations suggest that the experimentally observed linear relations between flows and forces, particularly in the case of oxidative phosphorylation, may be due to a feedback regulation maintaining linear thermodynamic relations far from equilibrium. This regulation may have come about as the consequence of an evolutionary drive towards higher efficiency.

Details

Language :
English
ISSN :
0301-4622
Volume :
18
Issue :
2
Database :
MEDLINE
Journal :
Biophysical chemistry
Publication Type :
Academic Journal
Accession number :
6226327
Full Text :
https://doi.org/10.1016/0301-4622(83)85003-0