Wednesday, November 26, 2008

Unrelated

So yesterday my friends and I got into a minor discussion about animals and how all they are are nutrient processing intestinal tracks on wheels - brains are nice but not mandatory. One of them qualified this statement by saying that animals all at least have a central nervous system, and I was all like "Nuh-uh-uh, not bacteria." Then everyone said that bacteria were not animals, but I condescendingly disagreed over and over again. Of course, it turns out bacteria are as far away from animals as you can get, much further than plants, and even more distantly related than archaea, which share some metabolic processes with eukaryotes (multicellular organisms.)

Bacteria are freaking crazy! Look at this chart showing the structure of bacteria's protein enclosed organelles. It zooms in on the structure from left to right. On the left we have a bacteria with organelles visible within it. By the time we get to the right you can see actual atoms in one huge molecule. Bacteria aren't that far removed from atoms just floating around, relatively! It's close enough that you can almost visualize a group of atoms just following out their chemically reactive duty, and that's life! That large collection of interacting atoms is alive!

You know the flagella that some bacteria have? Bacteria don't have cells, and therefore don't have traditional muscles. How does a flagella work? "Flagella are driven by the energy released by the transfer of ions down an electrochemical gradient across the cell membrane" So basically the flagella is just an inert piece of filament, which flails in response to a bacteria based motor. It's similar to a muscle, just it's made directly out of molecules rather than cells.

To change gears slightly, now check out myxobacteria. When these bacteria find themselves in an environment where nutrients are scarce (and at this level, nutrients are just molecules (which are just atoms (which are not alive)) that the bacteria collects to make more bacteria) these myxobacteria send signals to neighboring bacteria and join together. They organize themselves by releasing chemicals and different bacteria take on different tasks to form a fruiting body. This fruiting body creates spores that remain dormant until nutrients return to that environment, and they hatch at the same time, ensuring that the bacteria always have a group available. That's a primitive multicellular organism! That's what we humans are! Albeit not primitive.

That's all pretty exhausting to think about, isn't it? Do you know why it's exhausting? Whenever you learn, you are physically changing the structure of your brain. You have to spend a bunch of chemical energy to go in there and reconnect synapses. I had to go in and modify a bunch of misconceptions I had gathered somewhere that bacteria are simple animals (well, they are, but not semantically.) The brain I had this morning is a different shape than the one I have now, after noticing some parts of the brain which were not reflecting reality and concentrating some energy to go in and adjust it.

Isn't that CRAZY?