| Autor: |
Ciobotarescu S; Laboratoire de Photonique d'Angers EA 4464, Université d'Angers, Physics Department, 2 Boulevard Lavoisier, 49045 Angers, France.; Gheorghe Asachi Technical University of Iasi, Department of Natural and Synthetic Polymers, 73 Professor Dimitrie Mangeron Street, 700050 Iasi, Romania., Bechelli S; Laboratoire de Photonique d'Angers EA 4464, Université d'Angers, Physics Department, 2 Boulevard Lavoisier, 49045 Angers, France., Rajonson G; Laboratoire de Photonique d'Angers EA 4464, Université d'Angers, Physics Department, 2 Boulevard Lavoisier, 49045 Angers, France., Migirditch S; Laboratoire de Photonique d'Angers EA 4464, Université d'Angers, Physics Department, 2 Boulevard Lavoisier, 49045 Angers, France.; Physics and Astronomy Department, Appalachian State University, Boone, North Carolina 28608, USA., Hester B; Physics and Astronomy Department, Appalachian State University, Boone, North Carolina 28608, USA., Hurduc N; Gheorghe Asachi Technical University of Iasi, Department of Natural and Synthetic Polymers, 73 Professor Dimitrie Mangeron Street, 700050 Iasi, Romania., Teboul V; Laboratoire de Photonique d'Angers EA 4464, Université d'Angers, Physics Department, 2 Boulevard Lavoisier, 49045 Angers, France. |
| Abstrakt: |
We investigate the dependence of the displacements of a molecular motor embedded inside a glassy material on its folding characteristic time τ_{f}. We observe two different time regimes. For slow foldings (regime I) the diffusion evolves very slowly with τ_{f}, while for rapid foldings (regime II) the diffusion increases strongly with τ_{f}(D≈τ_{f}^{-2}), suggesting two different physical mechanisms. We find that in regime I the motor's displacement during the folding process is counteracted by a reverse displacement during the unfolding, while in regime II this counteraction is much weaker. We notice that regime I behavior is reminiscent of the scallop theorem that holds for larger motors in a continuous medium. We find that the difference in the efficiency of the motor's motion explains most of the observed difference between the two regimes. For fast foldings the motor trajectories differ significantly from the opposite trajectories induced by the following unfolding process, resulting in a more efficient global motion than for slow foldings. This result agrees with the fluctuation theorems expectation for time reversal mechanisms. In agreement with the fluctuation theorems we find that the motors are unexpectedly more efficient when they are generating more entropy, a result that can be used to increase dramatically the motor's motion. |
