Efficiency of molecular motors at maximum powerT. Schmiedl and U. Seifert
II. Institut für Theoretische Physik, Universität Stuttgart - 70550 Stuttgart, Germany, EU
received 15 April 2008; accepted in final form 6 June 2008; published August 2008
published online 17 July 2008
Molecular motors transduce chemical energy obtained from hydrolizing ATP into mechanical work exerted against an external force. We calculate their efficiency at maximum power output for two simple generic models and show that the qualitative behaviour depends crucially on the position of the transition state or, equivalently, on the load distribution factor. Specifically, we find a transition state near the initial state (sometimes characterized as a "power stroke") to be most favorable with respect to both high power output and high efficiency at maximum power. In this regime, driving the motor further out of equilibrium by applying higher chemical potential differences can even, counterintuitively, increase the efficiency.
05.70.Ln - Nonequilibrium and irreversible thermodynamics.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
87.16.-b - Subcellular structure and processes.
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