On May 14, 2014, at 12:09 PM, Jeffrey Schwartz <xxxxxx@gmail.com> wrote:

> What about Iron?
>
> I know there's iron in hemoglobin, so there's some cellular mechanism
> for handling it at least a little bit.
>

A very specific state of iron, which is there because of it’s wonderfully mutable affinity for oxygen, carbon dioxide and less happily, cyanide and carbon monoxide…when it’s held captive in the heme cage, and globin prison. Hemoglobin is to iron what a nuclear reactor is to unconstrained fission.

Iron is a *very* reactive metal. Elemental Fe gobbles up oxygen like a fiend, a very very hotly burning fiend. Note the bessemer reaction which converts iron to steel is strongly EXO-thermic.

That's why thermite does what it does…we’re just so used to iron being instantly coated with a film of iron oxide that we think of it as inert and stable.

Now, if you’re talking about anaerobes, yes something like that could happen..we have iron-reducing bacteria here on earth, as anyone who’s ever drunk skunky water from a well can attest.

None of them reduce it all the way to metallic iron, though.

In any sort of aerobic environment, though the best an organism’ll accomplish is rust scales or claws…not very useful.

--
Bruce Johnson
University of Arizona
College of Pharmacy
Information Technology Group

Institutions do not have opinions, merely customs