back to article Astroboffins' discovery gives search for early life a left hand. Or right

For the first time, astronomers have made an interstellar observation of a molecule that can exist in left- and right-handed versions – which could help unravel how life can come to exist. The discovery was made using two radio telescopes: Green Bank in the USA, and Parkes in Australia. What Brett McGuire (US National Radio …

  1. Voland's right hand Silver badge

    As Science notes, propylene oxide isn't an organic molecule;

    WHAAAAT?

    It is not life related, but it is organic all right - chemistry of the hydrocarbon compounds has always been called organic chemistry. We studied it as a part of the organic chemistry course, the part dealing with radical polymerization reaction (*) Not as much fun as peroxide radical reactions, but fun none the less.

    *Did this trigger the POLICE ATTENTION - radical mentioned, report to thought police dragnet? I bet it did. Such is life when weapons of mass instruction are loaded into your brain. If that did not, peroxides definitely did

    1. Kanhef
      Boffin

      Re: As Science notes, propylene oxide isn't an organic molecule;

      To be pedantic, organic chemistry originally was the study of compounds found in living things, and inorganic chemistry was everything else. After Friedrich Wöhler demonstrated that urea (a known organic chemical) could be synthesized from inorganic compounds, they had to scrap that definition and redefined organic chemistry to be about carbon instead.

  2. Anonymous Coward
    Anonymous Coward

    It would have been nice if journalists reporting on science had some scientific knowledge ..

    ... or at least run their copy past a scientist before going to press.

    Specifically:

    While the mirror-image molecules will behave the same in some ways – melting and freezing points, for example, or their reactions to light ...

    Enantiomers (mirror image copies of a chiral molecule) do in fact interact differently with light. With linearly polarized light, they will rotate the polarization plane in the opposite direction; with circularly or elliptically polarized light, they will absorb light to a different degree.

    For an entertaining, if a little dumbed-down introduction, feel free to peruse Wikipedia articles on Circular Dichroism and Optical Rotation.

    1. Mage Silver badge

      Re: Enantiomers (mirror image copies of a chiral molecule)

      Natural sugars are sweet.

      A right handed synthetic sugar isn't sweet.

      You can use a bright light and two polarisers (perhaps two pairs of sunglasses) and sugar solution to test this at home if you can get or make the non-sweet synthetic sugar.

      1. This post has been deleted by its author

        1. Christopher Lane

          Re: Enantiomers (mirror image copies of a chiral molecule)

          That being the case why aren't all diet food stuffs made with left handed sugar...all the sweetness but none of the sin (or aspartame created cancer or sorbitol bottom burps)!

          1. This post has been deleted by its author

            1. Stevie

              Re: Enantiomers (mirror image copies of a chiral molecule)

              And L-tryptophan didn't work out so well either.

  3. BrazzaB

    As Science notes, propylene oxide isn't an organic molecule;

    Come on Richard, don't let The Reg down!

    Propylene oxide is an organic compound!

    Science states: 'And though it isn't directly involved in biochemical reactions' - which means that organic life does not use this molecule, but it is organic as it contains hydrogen and carbon, just as Right Hand states.

    1. Richard Chirgwin (Written by Reg staff)

      Re: As Science notes, propylene oxide isn't an organic molecule;

      Well, thank you. I'll make a suitable edit immediately!

      (Knew I should have paid attention that day)

      Richard C

      1. imanidiot Silver badge

        Re: As Science notes, propylene oxide isn't an organic molecule;

        Not just that day ;)

  4. adnim
    Happy

    I know, obvious is not scientific proof,

    but I can live with this...

    "All the amino acids in living creatures are left-handed, which is the bit that interests astrophysics: why did Earth end up with those molecules and not others?"

    Possible answer in following paragraph?

    "Chiral molecules have been found in bits of asteroid, and left-handed forms typically dominate"

    1. Tom 7

      Re: I know, obvious is not scientific proof,

      Typically dominate? But by what amount? I have a problem with people saying its a mystery why all life is made of left handed amino acids. Its not - if the first replicating molecule was left handed then everything that follows will be left handed. Its 50-50 so not 'astronomical' at all.

      If we find anything that suggests there is a cosmological/quantum reason for chirality that is a different matter but will have little influence on how we work out how life started.

      1. Cuddles

        Re: I know, obvious is not scientific proof,

        "Typically dominate? But by what amount? I have a problem with people saying its a mystery why all life is made of left handed amino acids. Its not - if the first replicating molecule was left handed then everything that follows will be left handed. Its 50-50 so not 'astronomical' at all."

        No, it's not 50-50. That would only be the case if left and right chirality were equally common, which is exactly what "left-handed forms typically dominate" says isn't the case. And it's not simply down to what "the first" self-replicating molecule was like, because there's no reason to assume there was just one. All life (that we know of) descends from a common ancestor, but that simply means that only one primordial replicator was successful enough to have ancestors survive to today. There could have been numerous originating events, with most families dying out some time between then and now (although realistically they must have died out before the fossil record becomes reliable). Availability of resources is a major factor in how successful life is, so it's not just a simple probability of what the first self-replicator is like, but also how much of the "food" in the environment it's able to use. Even if a right-handed self-replicator happens to occur, if the majority of molecules around it are left-handed and therefore useless to it it has a much lower ability to survive and replicate.

        1. Mark 85

          Re: I know, obvious is not scientific proof,

          So then it's possible that life started and is thriving somewhere else based on right-handed molecules? Just musing over morning coffee and marveling at these latest discoveries.

          1. Michael H.F. Wilkinson Silver badge
            Joke

            50-50?

            More likely a million to one.

        2. Primus Secundus Tertius

          Re: I know, obvious is not scientific proof,

          The textbooks tell us that if a molecule with L- and R- forms is synthesised in the lab from non-chiral components, then equal quantities of each will be produced. Some chiral molecules if left in the lab will racemize: turn into equal amounts of L- and R-. That is the equilibrium state of affairs.

          Biosynthesis uses enzymes which themselves are L- or R- and so produce one result only.

          I have wondered what might happen in a steady-state non-equilibrium situation: for example, if water was slowly streaming through a system. Then a chance fluctuation might lead to a build-up of one chirality rather than the other. Needs suitable experiments, of course.

    2. FrogsAndChips Silver badge
      Holmes

      Re: Possible answer in following paragraph?

      That only shifts the question to: "Why do left-handed forms typically dominate in asteroids?", which the data found in Sagittarius B2 could help provide an answer for.

  5. The March Hare
    Happy

    left-handed

    Hah! so $Deity was left handed too!

    Yay for us downtrodden sinister people - it's about time!

  6. willi0000000

    left . . . right . . . does everything have to be political these days?

    1. Anonymous Coward
      Anonymous Coward

      left . . . right . . . does everything have to be political these days

      Look on the bright side: at least with molecules you won't get an extreme left or an extreme right enantiomer.

      1. John Brown (no body) Silver badge
        Alien

        Of course, however, on the gripping hand...

        <mutters> bloody bilateral symmetry bigots!

        1. Anonymous Coward
          Alien

          there's that Mote in your Eye Again, calm down

  7. Anonymous Coward
    Anonymous Coward

    Propylene oxide or Propane Oxide

    Interesting the continued use of trivial naming is still so common. Under the IUPAC naming system we should be calling this propane oxide. But a quick Google search shows that the US still seems to stick with trivial naming.

  8. David Pollard

    Parity violation in chiral molecules

    There are theoretical reasons to expect that the enthalpies of enantiomers will be very, very slightly different as a result of non-conservation of parity in the weak interaction. Experimental verification has so far proved rather tricky, but measurement of the relative amounts of pairs of chiral molecules in distant gas clouds could shed light on this curious aspect of the universe.

    The spatial symmetry of most physical laws says that when achiral molecules form chiral products, the system as a whole will stay racemic. However, it may be that the universe is handed, and that spacial symmetry which we take for granted is actually slightly broken.

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