The Song of the Cell

By decoding, I mean that molecules within a cell read certain sections of the genetic code, like musicians in an orchestra reading their parts of a musical score—the cell’s individual song—thereby enabling a gene’s instructions to become physically manifest in the actual protein.

pathology—the study of human diseases, and their causes—

And that behavior, in turn, manifests as the behavior of the organism. The metabolism of an organism reposes in the metabolism of the cell. The reproduction of an organism reposes in the reproduction of a cell. The repair, survival, and death of an organism repose in the repair, survival, and death of cells. The behavior of an organ, or an organism

A cell thus transforms information into form; genetic code into proteins.

Life’s definition, as it stands now, is akin to a menu. It is not one thing but a series of things, a set of behaviors, a series of processes, not a single property. To be living, an organism must have the capacity to reproduce, to grow, to metabolize, to adapt to stimuli, and to maintain its internal milieu. Complex, multicellular living beings al

True knowledge is to be aware of one’s ignorance.1 —Rudolf Virchow, letter to his father, ca. 1830s

What is a cell, anyway? In a narrow sense, a cell is an autonomous living unit that acts as a decoding machine for a gene. Genes provide instructions—code, if you will—to build proteins, the molecules that perform virtually all the work in a cell. Proteins enable biological reactions, coordinate signals within the cell, form its structural elements

the 1670s, Antonie van Leeuwenhoek, a cloth merchant in Delft, needed an instrument to examine the quality and integrity of thread.

But a cell is not merely a gene-decoding machine. Having unpacked the code by synthesizing a select set of proteins that is encoded in its genes, a cell becomes an integrating machine. A cell uses this set of proteins (and the biochemical products made by proteins) in conjunction with one another to start coordinating its function, its behavior (mo