I find it mind-boggling that such tiny molecules can affect my physical (and mental, if you’re Descartes) state so much. Especially when I compare my cognition to computers.
They won’t need ad hoc chemical adjustments to increase working memory.
If you need more, you just use more compute.
How many molecules per neuron do you get from a cup?
So, how tiny is this miraculous molecule, exactly?
Well, mass-wise, it has 8 carbons, 10 hydrogens, 4 nitrogens, and 2 oxygens.
So that’s 2 * (48 + 10 + 28 + 16) = 204 Daltons.
How many caffeine molecules are there in a cup of coffee? Is there enough for each neuron in the brain
A factoid I remember is that an espresso has roughly 100 mg of caffeine (from roughly 7g of coffee)
A dalton is 1.66 * 10−27 kg. So one caffeine molecule is some 3*10−25 kg
100 mg is 10−4 kg.
That’s roughly 3*1020 molecules.
Or it may also be completely off.
Anyway, I believe there’s about 100 trillion neurons in the brain (which calls for another Fermi some other time). That’s 10^14 cells.
Which means that, in principle, there’s plenty for each neuron. If the distribution were perfect, every neuron could get 10 million of them.
Why did caffeine evolve?
This picture famous picture of a web weaved by a spider on caffeine provides a clue.
Some more questions
How many adenosine receptors does a human neuron have?
How does the coffee plant synthesize caffeine?
Why does caffeine increase heartbeat?
Why does coffee taste bitter?