NASA discovers unique new life form

Edit: wait, this bacteria does use ATP, so I'm confused as to why Arsenic is not poisonous to these bacteria. But I do know that it doesn't have any real application for medical science, this is essentially just support for the idea that life does not need earth's exact chemical makeup to exist, which was already present.

The bacteria could be making nucleotide tri-arsenates (e.g. Adenosine tri-arsenate) and using those for energy.

Just a guess, though.