I used to ask the question in biology class: why do we eat?

The logical and most common answer, of course, was “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 were at bottom, making statements about the conditions of their 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  muscles, glands, and nerves.”

Well, I was wrong. Just discovered: 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 rapt in the real world and not so interested in reading fiction.

Published by fred

Fred First holds masters degrees in Vertebrate Zoology and physical therapy, and has been a biology teacher and physical therapist by profession. He moved to southwest Virginia in 1975 and to Floyd County in 1997. He maintains a daily photo-blog, broadcasts essays on the Roanoke NPR station, and contributes regular columns for the Floyd Press and Roanoke's Star Sentinel. His two non-fiction books, Slow Road Home and his recent What We Hold in Our Hands, celebrate the riches that we possess in our families and communities, our natural bounty, social capital and Appalachian cultures old and new. He has served on the Jacksonville Center Board of Directors and is newly active in the Sustain Floyd organization. He lives in northeastern Floyd County on the headwaters of the Roanoke River.

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