Enzymes Exposed

Clearer views of the cell’s movers and shakers threaten a century-old mainstay of biology

In some ways, cells are a lot like cities. Maps of a cell’s innards depict thoroughfares linking factories that build large molecules to post offices where those molecules are packaged up and shipped out, for example. The cell’s denizens — proteins and other molecules — shuttle around busy cellular byways like people on the street, meeting up, interacting and keeping the whole enterprise going.