A structure–dynamics relationship in ratcheted colloids: resonance melting, dislocations, and defect clusters

We consider a two dimensional colloidal dispersion of soft-core particles driven by a one dimensional stochastic flashing ratchet that induces a time averaged directed particle current through the system.

POWER AND EFFICIENCY OF F1-ATPase MOLECULAR MOTOR

We present the study of the energetics of the F1-ATPase rotatory molecular motor. The dynamics of this machine are described by a overdamped Langevin equation with a dichotomous flashing ratchet potential whose transition rates are controlled by an analysis of the chemical and physical steps. The model predictions on the observable angular velocity are in good agreement with the experimental data. Inspired by these results we extend our approach to study the energetics of this motor. Power and efficiency are analyzed for different experimental situations which can be tested in experiments.

THE MEAN VELOCITY OF TWO-STATE MODELS OF MOLECULAR MOTOR

The motion of molecular motor is essential to the biophysical functioning of living cells. This motion can be regarded as a multiple chemical state process. So, mathematically, the motion of molecular motor can be described by several coupled one-dimensional hopping processes or by several coupled Fokker–Planck equations. To know the basic properties of molecular motor, in this paper, we will give detailed analysis about the simplest case in which there are only two chemical states. Actually, many of the existing models, such as the flashing ratchet model, can be regarded as a two-state model. From the explicit expression of the mean velocity, one can see that the mean velocity of molecular motor might be non-zero even if the potential in each state is periodic, which means that there is no energy input to the molecular motor in each of the two states. At the same time, the mean velocity might be zero even if there is non-trivial energy input. Generally, the velocity of molecular motor depends not only on the potentials (or corresponding forward and backward transition rates) in the two chemical states, but also on the transition rates between them.

DETERMINISTIC COLLECTIVE DIRECTIONAL TRANSPORT IN ONE-DIMENSIONAL FLASHING RATCHET POTENTIALS

In the absence of thermal fluctuations and other external forces, a single particle will be pinned at the bottom of a flashing ratchet potential under the overdamped condition. Unidirectional motion becomes possible if there exist interactions among particles. In this paper, the overdamped directed motion of a dimer with two heads in a flashing ratchet potential is investigated. We propose the mechanism to reveal how two heads of the dimer cooperate and help each other to move processively. The necessary condition of directed motion is analytically given, which is in good agreement with numerical simulation results. Furthermore, the resonant steps of the current are observed and discussed. The scenario and the results proposed in this paper may shed light on the elaborations of artificial molecular motors.