Knowing how a living cell works means knowing how the chemistry inside the cell changes as the functions of the cell change. Protein phosphorylation, for example, controls everything from cell proliferation to differentiation to metabolism to signaling, and even programmed cell death (apoptosis), in cells from bacteria to humans. It’s a chemical process that has long been intensively studied, not least in hopes of treating or eliminating a wide range of diseases. But until now the close-up view - watching phosphorylation work at the molecular level as individual cells change over time - has been impossible without damaging the cells or interfering with the very processes that are being examined.
