I used to ask the question in biology class: why do we eat?
The logical and most common answer, of course, wasÂ “because we get hungry.”
“But why do we get hungry” I asked them back?
“Because our stomachs are empty.”
You get the picture. And it went around like this until students understood that when they said “I’m hungry, I’m thirsty, I’m tired…” they wereÂ at bottom, making statements about the conditions of theirÂ cells.
And I would from there go on to describe the universal chemistry whereby electrons were stripped from “food” consumed in one way or another to eventually be picked up by the “universal energy currency called ATP.”
“All organisms from microbes to monkeys follow the same path from food energy to ATP energy to operate Â muscles, glands, and nerves.”
Well, I was wrong. Just discovered:Â bacteria (apparently quite a few diverse species across a range of habitats) that use electrons directly to do things that require energy: growing, moving, reproducing.
So, technically I suppose, these organisms don’t EAT. They bypass that act and obtain and apparently make use of energy directly in the form of electrons from their environment without stripping them in the Krebs cycle.
This is perhaps one of the most astounding discoveries of recent decades in a world where we tend to think we’ve seen it all.
This is why I stay raptÂ in the real world and not so interested inÂ reading fiction.