Just as people endlessly calculate how to upsize or downsize, bacteria continually adjust their volume (their stuff) to fit inside their membrane (their space). But what limits their expansion? The answer will surprise you.
New work shows that bacteria (and probably other cells as well) don’t double in mass before dividing. Instead they add a constant volume (or mass) no matter what their initial size. A small cell adds the same volume as a large cell. By following this rule a cell population quickly converges on a common size.