The achiral key to life

MichaelMcF
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The achiral key to life

 From New Scientist.

 

Quote:

 

One theory for the presence of single enantiomers in nature is that slight excesses of one enantiomer in the prebiotic world could have been increased further by autocatalysis, a reaction where the product promotes its own formation. These slight initial excesses may be extraterrestrial in origin, as they have been observed for a variety of chiral molecules found in meteorites. 

However, Kenso Soai and co-workers from the Tokyo University of Science claim that the high deuterium content in meteoritic environments could mean that achiral compounds are just as important. 'Even the most simple achiral amino acid, glycine, becomes chiral when one of the methylene group's hydrogen atoms is substituted by deuterium,' explains Soai. 'Meteoritic chiral amino acids due to deuterium substitution may exist and may constitute the extraterrestrial origin of chirality.' 

 

 

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Hambydammit
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 Does temperature have an

 Does temperature have an important role in meteoric deuterium content?  I was chatting in skype last night about the theory that most of earth's water came from comets, and was introduced to the theory that a comet's place of origin in the solar system can be estimated by the amount of certain isomers present, as being too close to the sun would prevent certain ones from forming.

It seems like the two topics might overlap.

 

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Answers in Gene...
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You mean isotopes. But

You mean isotopes. But yah, isotopes are affected by temperature.

 

One of the ways that we measure global temperature in the distant past is by analyzing the ratio of oxygen and hydrogen isotopes in ice cores. The thinking is that heavier water molecules are less likely to vaporize in cooler climates and thus they can provide one measure of global temperature.

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Hambydammit
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Grrr... chemistry 1000 seems

Grrr... chemistry 1000 seems like years and years ago...

Wait.  It was years and years ago.  I took my last chemistry course in... let's see... 1991, I think.  Goddamn.

Yes... I meant isotope.  And thanks for the info.

Atheism isn't a lot like religion at all. Unless by "religion" you mean "not religion". --Ciarin

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