Form and Motion

Abstract

Cells are inventive architects. Using only invisibly small building blocks, cells fabricate tough fibers of protein, providing flexible strength to tendons and cartilage. By embedding mineral crystals in these fibers, cells build bones and teeth—stony structures strong enough to last millions of years. By filling themselves to bursting with vanishingly thin ropes of protein, skin cells form a flexible, insulating coat. Linking these ropes tightly together provides additional strength for fingernails. A dense scaffold of protein supports and directs the convoluted inner world of each cell. To build these elaborate structures, some thousands of times larger than an individual cell, one can find examples of any engineering principle in use today. Fences are built, railways are laid, reservoirs are filled, and houses are constructed complete with rooms, doors, windows, and even decorated in attractive colors. Lap joints, buttresses, waterproofing, reinforcing rods, valves, concrete, adhesive—each has a molecular counterpart.