Energy in Molecular Machines

Friday, April 10 2015 10:00 AM – AMPEL 311

M.A. Van Hove

Institute of Computational and Theoretical Studies & Department of Physics,

Hong Kong Baptist University, Hong Kong SAR, China

Abstract

Molecular machines are gaining increasing interest from biological to energetic perspectives. They promise to convert energy and control mechanical motion at length scales down to the nanometer. Some molecular machines cause reciprocal motion, as in muscles and switches, while others cause rotational motion, as in flagellae: we discuss theoretical models of both.

Nature developed a variety of molecular machines to convert energy and control motion. These natural machines tend to be complex and robust, due to the need to operate reliably for long times in variable biological environments.

In the last few decades, scientists have synthesized a wide range of new, relatively simpler molecular machines and learned to control and observe some of their important motions, mostly in solution. Increasingly, molecular motors have also been investigated at solid surfaces, allowing the use of surface science techniques for studying monolayers of well-oriented molecules. Nanoscience techniques have added further possibilities.

We shall discuss basic issues of the operation of molecular motors, including energy conversion steps, continuous energy supply, the role of thermal energy, intentional start and stop of motion, and unidirectionality of motion. Without intentional control of these aspects, motors create random motion and are largely useless.