The physics of molecular motors

Molecular motors convert chemical energy into mechanical force and movement . Operating at energies just above those of the thermal bath, these motors experience large fluctuations, and their physical description must be neces sarily stochastic. Here, motor operation is described as a biased diffusion on a potential energy surface defined by the interactions of the motor wit h its track and its fuel. These ideas are illustrated with a model of the r otary movement of the F-o motor.