[Kellerjl02]

As you probably know, chirality matters when it comes to living things on this planet. Things taste the way they do based on their chirality (caraway vs spearmint for example), and our RNA and DNA all have the same handedness. I was wondering what would happen if there was a genesis of life with the opposite handedness. Could such a thing happen? Say a planet, that has all of the same conditions as ours did when live first coalesced here, was just become dotted with life. Is it possible that that life lineage could end up with an opposite chirality to ours and still, ya know, exist? Or is there something about our building blocks that need a specific chirality from the start. I know that our building blocks now need to be homochiral just so we can keep on going, but the point of my question is would it be possible for everything to have been flipped the other way and just end up with essentially the same results, as far as molecular interactions and enzymatic action  and all that jazz? Supposing that everything was flipped chiralitywise would we get identical or near identical results? Is there anything that precludes anticipated interactions based on chirality if everything is flipped? I'm just a curious person and I don't study chemistry collegiately, so if I am using the wrong vocabulary, then please clue me in if you can. Thanks for your consideration. I tried to search for similar questions on the web and couldn't find anything, if you know of a resource specific to my query then please point me in the right direction. My reason for interest is purely extracarricular.

[Dan]

Flipping everything should result in identically functioning life (just everything in mirror image).

As far as I'm aware, the orgin of biological homochirality is generally thought to have been a random decision (in terms of the chirality sense or "handedness" that was favoured).

Here is a nice article you may find interesting: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857173/pdf/cshperspect-ORI-a002147.pdf