how molecules formed

Discussion in 'Biology & Genetics' started by paddoboy, Sep 29, 2015.

  1. paddoboy Valued Senior Member

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    Synthesizing how molecules formed at dawn of life on Earthby Staff WritersBarcelona, Spain (SPX) Sep 25, 2015

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    This is an E.coli FSA enzyme. Image courtesy CSIC. For a larger version of this image please gohere.
    Researchers from the Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), with support from the Nuclear Magnetic Resonance Service of the Universitat Autonoma de Barcelona (UAB) have developed a method for synthesising organic molecules very selectively, by assembling simple molecules and using an enzyme from E. coli (FSA: D-fructose-6-phosphate aldolase), which acts as a biocatalyst.

    This is a significant step forward since it replicates the formation of carbohydrates in conditions resembling those that presumably initiated life on the Earth (prebiotic conditions) and because it allows relatively large organic molecules to be obtained very selectively and efficiently.

    Furthermore, it is a process with few steps, that does not use organic solvents and generates no waste, and it has great potential in chemistry, especially for obtaining molecules and active ingredients of interest (drugs, supplements, etc.).


    more at.....
    http://www.spacedaily.com/reports/N..._formed_at_the_dawn_of_life_on_Earth_999.html
     
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  3. danshawen Valued Senior Member

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    Awesome. Another large piece of the chemical puzzle of the primordial soup.

    No hard and fast rules for the prediction of catalysis (biochemical or otherwise) exists to the best of my knowledge. I once lost a science fair for attempting to investigate this. Obviously, there was a simple scope issue. At the time, I evidently believed science could conquer any problem if nature can. Not quite a fair match, to say the least.
     
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  5. exchemist Valued Senior Member

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    I read the link. What I do not fully understand is why they say this replicates conditions resembling the prebiotic era. The gizmo they are using in this work is an enzyme, after all, so itself the product of complex evolutionary biochemistry.

    As I read it, the issue may be that researchers did not previously know what this enzyme was for - it seems to be an ancestral one that was just there - so now they speculate it once had a role in carbohydrate synthesis, at some earlier stage in the development of life. But that does not, to me, look like an insight into anything that may have happened under prebiotic conditions.

    Am I missing something here?
     
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  7. timojin Valued Senior Member

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    Which carbohydrate molecules were synthesized ? Did they say they actually produced pentose and hexose ? I must have missed something.
     
  8. rpenner Fully Wired Valued Senior Member

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    http://www.nature.com/nchem/journal/v7/n9/full/nchem.2321.html
     
  9. timojin Valued Senior Member

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  10. rpenner Fully Wired Valued Senior Member

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    No, sorry. Unlike the math/physics community, the chemistry community is a bit shyer about sharing pre-prints and open copies.
     
  11. paddoboy Valued Senior Member

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    I'm sure you would know that far better than I

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    ...I don't know, but will try and follow up on the article and see what more info I can find.
     
  12. timojin Valued Senior Member

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    I Believe this is the original work , and I am not sure if the Spanish work or an Englishman by the name Clarke have advanced any further.
    Synthesis of Sugars by Aldolase-Catalyzed, Condensation Reactionsl Chi-Huey Wong and George M. Whitesides* Departments of Chemistry, Massachusetts Institute of Technology and Haruard Uniuersity, Cambridge, Massachusetts 02138 Receiued March 15. 1983

    https://gmwgroup.harvard.edu/pubs/pdf/158.pdf
     
  13. rpenner Fully Wired Valued Senior Member

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  14. timojin Valued Senior Member

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    I don't think you are missing it is just sensationalism from a publisity magazin. similar work was done 30 years ago
     
  15. exchemist Valued Senior Member

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    From reading the abstract and introduction, this earlier paper seems to be about extracting (from E coli) and purifying an enzyme called DERA (deoxyribose-5-phosphate aldolase), and then using it to synthesise a variety of what they call sugar analogues. A natty piece of biochemical synthesis, but no reference to anything about primordial life.

    The news report in the OP concerns a different but similar enzyme (i.e. another aldolase) from E coli, called D fructose-6-phosphate aldolase, which they call "FSA". It's the primordial life bit of the report that I don't really get at the moment. It seems to follow from a comment from one of the researchers at Barcelona, saying: "The process is a simple one, mimicking the prebiotic formation of carbohydrates from compounds that were probably around in the world before life began", (Teodor Parella, of the UAB). I can understand this at one level, in the sense that these aldol syntheses are in principle quite simple reactions, of comparatively simple molecules. But they point out the difficulty and inefficiency of ordinary chemical synthesis of these sugars, whereas this enzyme is far more efficient and moreover introduces chirality, which we know is crucial in biochemistry, whereas conventional chemistry would just give you a racemic mixture.

    So it seems to me that the puzzle of prebiotic assembly of chiral molecules like this is not really addressed. In effect they say that, once you have FSA around, it becomes dead easy......but FSA is itself a fairly sophisticated product of evolution.

    "This shows the need for further research........"
     
  16. Dinosaur Rational Skeptic Valued Senior Member

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    A bit off topic, but related.

    I have been amused by Posters who claim extraterrestrial origins for life molecules as though this explains their origin rather than merely pushing the explanation back to another environment.
     
  17. exchemist Valued Senior Member

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    Same here.

    Of course it does not not mean it can't be true - one has to follow the evidence- but if it is, how depressing, since that will make it even harder to find evidence for how it originated.
     

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