Toy model for molecular motors

TL;DR

This paper introduces a simplified hopping model for molecular motors, analyzing particle current, mobility, diffusion, power, and efficiency, providing insights into their fundamental physical behavior.

Contribution

It presents a novel toy model with asymmetric and uniform hopping states to study molecular motor dynamics and efficiency.

Findings

Explicit current calculation as a function of state change rate

Investigation of Einstein relation between mobility and diffusion

Model's efficiency found to be relatively small

Abstract

A hopping model for molecular motors is presented consisting of a state with asymmetric hopping rates with period 2 and a state with uniform hopping rates. State changes lead to a stationary unidirectional current of a particle. The current is explicitly calculated as a function of the rate of state changes, including also an external bias field. The Einstein relation between the linear mobility of the particle and its diffusion coefficient is investigated. The power input into the system is derived, as well as the power output resulting from the work performed against the bias field. The efficiency of this model is found to be rather small.