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Comment by gus_massa | Hacker News Reader

> As you may recall from high school biology, almost every living organism consumes sugar to survive. When it gets right down to it, everything you eat is ultimately converted or digested into single molecules of glucose.

This is an oversimplification. Some bacteria have very weird metabolism. (Or, from the other point of view, some bacteria think that we have a very weird metabolism :) ). They oxidize and reduce different kind of compounds to obtain energy. More info: http://en.wikipedia.org/wiki/Microbial_metabolism

The [extremetech] article has very few details and I think that it's misleading. I can't find the original research article.

There are some interesting details in the video. (Is this a video of this experiment?) Apparently these bacteria use O2 (oxigen) and H2S (hydrogen sulfide). The metabolism is probably like: http://en.wikipedia.org/wiki/Microbial_metabolism#Sulfur_oxi...

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Definitely.

It should also be noted that any organism that uses oxidative phosphorylation for metabolism (humans included) technically use "pure energy in the form of electron flow" by having carrier molecules like NADH and FADH2 release electrons into the mitochondrial membrane. The electrons then flow through a few proteins, which use the electrons' energy to create a proton gradient in the mitochondrion, which is then used to create ATP (the "currency" of chemical energy in many cells).

I agree that the tone is a bit sensationalist. It is New Scientist, after all. But note that the article itself makes your point:

> That should not come as a complete surprise, says Kenneth Nealson at the University of Southern California, Los Angeles. We know that life, when you boil it right down, is a flow of electrons: "You eat sugars that have excess electrons, and you breathe in oxygen that willingly takes them." Our cells break down the sugars, and the electrons flow through them in a complex set of chemical reactions until they are passed on to electron-hungry oxygen.

> In the process, cells make ATP, a molecule that acts as an energy storage unit for almost all living things. Moving electrons around is a key part of making ATP. "Life's very clever," says Nealson. "It figures out how to suck electrons out of everything we eat and keep them under control." In most living things, the body packages the electrons up into molecules that can safely carry them through the cells until they are dumped on to oxygen.

> "That's the way we make all our energy and it's the same for every organism on this planet," says Nealson. "Electrons must flow in order for energy to be gained. This is why when someone suffocates another person they are dead within minutes. You have stopped the supply of oxygen, so the electrons can no longer flow."

Indeed, first thing I thought of was the radiation-using mushrooms at Chernobyl: http://www.sciencedaily.com/releases/2007/05/070522210932.ht...

Talk about a crazy energy source!

For that matter even humans have a weird metabolism compared to what the quote says - sugar/glucose is not the only source of energy: https://en.wikipedia.org/wiki/Ketosis

My thoughts exactly, although to be fair, the human body can't survive on ketones alone. Some cells cannot metabolise ketones and rely on glucose produced by the liver to function.

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