Fifty years ago, if a group of scientists were asked to define the key to life, the great majority would point to metabolism; how we obtain energy from food. However, adding all the required molecular components and stirring it up will not produce an organism. A more modern view of molecular biology is concerned with organization in time and space. How doe the molecules of life arrange themselves throughout the cell’s compartments, how do they move around, and communicate so as to synchronize their actions? We can ask this question because we can now inspect the working cell at a molecular level and take snapshots of its molecules doing their business.