The Molecular World

Abstract

An invisible world courses through every inch of your body. This is the world of molecules. Your molecules are tiny machines—millions of times smaller than machines in our familiar world—each performing one microscopic task. Each drop of your blood contains hundreds of different kinds of molecules: some transport food and air, others carry messages, others stand ready to repair an injury. In your eyes, a glittering solution of molecules refracts and focuses an image of light. A subtle change in the shape of another molecule captures this image like a sheet of film. At this moment, in your arms and hands, legions of tiny molecular motors are laboring to hold this book and to turn each page. Indeed, these words you are reading are recognized, sorted, and understood in a flurry of electrochemical impulses, organized by ranks of molecular switches. These everyday tasks—breathing, seeing, moving, and thinking—may be traced to the combined action of invisible molecules. Individually, each of your molecules is a delicate instrument. Together, they endow you with life.