2019 Volume 59 Issue 6 Pages 300-304
Molecular motors are nonequilibrium open systems that convert chemical energy to mechanical work. The nonequilibrium energetics of single molecule kinesin were investigated by measuring the motion of an attached probe particle and its response to external forces with optical tweezers. The sum of the heat dissipation estimated from the violation of the fluctuation-response relation and the output power was inconsistent with the input free energy rate, indicating that large internal dissipation exists. Here we introduce the theoretical basis of the dissipation measurement and our recent experimental results, discussing the physiological implications of the hidden dissipation in the kinesin motor.
