system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: how do living things move at a molecular level?

Sorry if its too complicated to ELI5

Edit: I'm asking, how can I control the atoms of the muscles in say, my finger? What do my brainwaves do to the atoms?
gpt
At the molecular level, molecules move around by brownian motion.  Brownian motion is essentially the random motion of molecules just bumping into each other.  Every time a molecule bumps into another energy is exchanged.  An easy way to think of it is to imagine tennis balls being flung around in a hurricane.  When the balls bounce into each other they change direction.

The trouble is, is that this motion is completely random.  Nature has found a few clever ways to turn this random motion into directional, generally by using "molecular ratchets". One example is kinesin motor protein.  This protein looks like a pair of legs, and walks along long rope-like structures called microtubules.  The neat thing about kinesin is that the front foot is always locked in place, and the back foot is allowed to freely move.  The random brownian motion pushes this foot in every direction, until it finds a foothold in front of the other leg.  The new front foot then locks in place, and the back foot gets released, so it can take another step.  This is one way that random atomic movements get turned into directional molecular movements.