Science Questions

Were Miller's results right- or left-handed??

Tue, 12th Jun 2012

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Android Neox, Second Life asked:

We know that the amino acids we use on Earth are all left handed. How about the molecules found in Stanley Millerís experiments? Were they of an even distribution of right and left handed forms or was there a bias?


Jeff -   No.  The amino acids that were made in the Miller experiment were equal handedness, what we call a racemic mixture.  That's what you expect from a pure chemical synthesis.  You only get handedness when you have some sort of interaction than in itself has some sort of handedness and in this experiment, there was no such interaction and so, you get completely equal handedness in the amino acids that are produced.

Chris -   I suppose that must give you confidence too, that the tubes havenít been contaminated because if you had seen all of one sort of handedness and not another, you'd know that probably the source was a biological source that have crept into the tube later.

Jeff -   Yes, that's correct because if there was any biological contamination, it would consist primarily of the left-handed amino acids and so, you should alter that equal mixture of abundances.  But there is also amino acids in this mixture that in fact, a majority of them are not found in living organisms, and so, you then rule out contamination on that basis alone.


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