Life’s Ratchet: How Molecular Machines Extract Order from Chaos

Below the calm, ordered exterior of a living organism lies microscopic chaos. Our cells are filled with molecular machines, which, like tiny ratchets, transform random motion into ordered activity, and create the “purpose” that is the hallmark of life. Tiny electrical motors turn electrical voltage into motion, nanoscale factories custom-build other molecular machines, and mechanical machines twist, untwist, separate and package strands of DNA. The cell is like a city—an unfathomably, complex collection of molecular workers creating something greater than themselves.