The Machinery of Life

"Even when living things are operating normally and humming along, it’s still beyond our ordinary understanding. You really have to stretch your powers of imagination to try to get a sense of what it is like inside of a cell. Ironically, textbooks can make that imagination more difficult. If they want to show how genes are used to make proteins, they show a very tiny, isolated piece of DNA, and then an isolated strand of RNA, and an isolated ribosome that uses the RNA to make a protein – as if that was all there was in the cell. But the fact is that every cell is actually crammed with molecules, all of which have really important things to do. Yes. I think that David Goodsell’s illustrations do a masterful job of giving you that sense of just what a mob scene it is inside of cells. It should raise some very important questions. Molecules actually have to move across the cell in order to do certain things. For example, in order to make a protein, you have to copy a gene, and then get that copy of RNA away from the DNA and off to other kind of factories in other parts of the cell. Well, how are you going to do that when you are packed tight in this crowd of other molecules? Molecules don’t know where to go – they don’t have a map – so how does that work? Scientists have some ideas about it, but they are still trying to figure out many of the fundamentals. It’s a very hard problem, and I think just one look at one of David Goodsell’s illustrations really drives home just how hard it is."