Amino Acids Created in Deep-Space-Like Environment

klevin writes "NASA scientists today announced the creation of amino acids, critical for life, in an environment that mimics deep space. The above link is the press release, with additional details here."

Comments

Haven't I seen this before?

[!ramirez]

Isn't this similar to what Stanley Miller and Harold Urey found in the 1960's with their spark-chamber experiment? While this seems to be stellar in nature, how much different is UV photolysis from electrical discharge as far as chemical reactions go?

Similar, more important

[Llywelyn]

There is a great deal of doubt whether the mixture of gases used in this experiment actually existed on earth: it assumes a reducing atmosphere, among other things that geology does not tell us.

More than one geologist, in fact, has noted that the only reason that they believe that there ever was a reducing atmosphere on Earth is because life is obviously here and the basic building blocks couldn't form in the presence of Oxygen.

At the same time, however, those amino acids couldn't form without the presence of an ozone layer--which requires free oxygen.

This is interesting and intriguing because it shows how these blocks could form in deep space and then arrive on Earth--since we already know that they can remain intact in their descent through the atmosphere.

It still doesn't even come *close* to answer the criticisms levied against abiogenesis (the formation of proteins, functional alleles, &c), but it is interesting and extremely significant over the Urey-Miller experiment.

Re:Similar, more important

[BlackGriffen]

If you had amino acids forming in deep ocean, then the lack of ozone layer wouldn't be a problem, would it? (honest question, sorry it can be read as rhetorical) As for the high oxygen levels in our atmosphere, is it possible that life is necessary to do that? I'm no chemist, but it's my understanding that oxygen is highly reactive, and thus incredibly good at 'oxidizing' (pun intended) things. It strikes me as odd that any planet would have a significant amount of O2 without some process putting it there (just like Cl2 isn't abundant). Thus it would stand to reason that on possible reason life spent so long in the oceans was because that the life in the ocean had to liberate enough O2 to get an ozone layer set up. It's my understanding, also, that the organism's work would simply be undone as the chemicals were released when it died. Thus, the formation of large carbon deposits (read: coal, oil, natural gas, and that methane impregnated ice) may have played a critical role in cooling the planet down; that is, assuming that the sun's temperature hasn't varied a whole lot over the past billion years or so (unlikely).

Just the musings of a college student who really should be sleeping.

BlackGriffen

Re:Big deal

[searleb]

Nope. The point is gone. Proteins are just lots of amino acids, connected by single bonds. The hard part is getting all those constituent atoms to form into the relatively complex amino acids.

As a protein/organic chemist, I say to you: why don't you try making that single bond? It's quite hard when you don't have a ribosome to do all the work for you.

Stanley Miller has been making amino acids (granted, the wrong way) since 1955. And he didn't even have his doctorate yet. Raw amino acids are easy- what's difficult is selecting the proper stereochemistry (amino acids have mirror images which are chemically identical but structurally different- life only uses one of the two mirror images (enantiomers)). If you condense the wrong enantiomer, or both enantiomers simultaneously, you get garbage out. Same problem with nucleic acids to DNA. In the end, this report is plagued with the same problems that Stanley Miller faced in 1955, sorry kids, deep space (or almost every other non-biological natural chemical synthesis) doesn't care about symmetry.

If you're interested in a brief history of Miller, why he's wrong, and what we think now, see my other post.

Re:Another blow against creationists

[JetJaguar]

I don't have the references handy, but IIRC, recently a whole class of organic, self-replicating molecules has been found, and they aren't that hard to make under the conditions most scientists believe the primordial earth had. The argument posited is that these simple molecules could easily have been the chemical starting point, eg. there was enough raw material for these molecules to form, and to reproduce themselves. They also have a relatively high probability of mutation and some of those mutations are non-destructive...

Now, they may not be functional proteins, nor DNA, or even genes, but it sounds like these molecules just might be the chemical starting point.