The Nature of Mechanical Devices in Biological Systems

Abstract

A mechanical device must have moving parts. Even the simplest lever turns about a fulcrum. A biological system clearly directs stress and strain so that action and information are transmitted in a deliberate spatial pattern. The question arises as to how this can be done at the molecular level. The available motions which must be built into a molecular machine are known to be side-chain motions (vibrations or rotations), segment motions (vibrations, rotations or lateral translations) domain motions (vibrations, rotations or lateral translations) and whole molecule movements. We know that the polymers involved are proteins, polysaccharides and polynucleotides. I have been concerned with the first two only. I shall describe some observations and views.