How DNA and proteins work

EVERYTHING ON Earth is made of atoms, most of which are closely packed together in the form of minerals. Life has its uses for minerals—ask a coral reef—but its essence lies in atoms arranged as distinct molecules and the way they interact.

Biological molecules are distinctive in various ways. One is that they can be very large indeed. The simple inorganic molecules that make up the air and the oceans typically contain only a few atoms, and often just two or three. Many biological molecules contain thousands. A few contain billions. These molecules are not just large, they are also precisely structured. Furthermore, those structures can be recreated with atom-by-atom accuracy.