Asymmetric Molecule, Key To Life, Detected In Space For First Time (yahoo.com)

schwit1 quotes a report from Yahoo News: Scientists for the first time have found a complex organic molecule in space that bears the same asymmetric structure as molecules that are key to life on Earth. The researchers said on Tuesday they detected the complex organic molecule called propylene oxide in a giant cloud of gas and dust near the center of the Milky Way galaxy. Akin to a pair of human hands, certain organic molecules including propylene oxide possess mirror-like versions of themselves, a chemical property called chirality. Scientists have long pondered why living things make use of only one version of certain molecules, such as the 'right-handed' form of the sugar ribose, which is the backbone of DNA. The discovery of propylene oxide in space boosts theories that chirality has cosmic origins. The scientists in the new study used radio telescopes to ferret out the chemical details of molecules in the distant, star-forming cloud of gas and dust. As molecules move around in the vacuum of space they emit telltale vibrations that appear as distinctive radio waves. Future studies of how polarized light interacts with the molecules may reveal if one version of propylene oxide dominates in space, the researchers said.

Comments

Not necessarily a single enantiomer

[Anonymous Coward]

When I first read this, I thought they had found a non-50:50 ratio of enantiomers, but it appears that they have simply detected the presence of propylene oxide in some form, which doesn't seem terribly surprising to me. It would be fascinating if they did discover that one enantiomer was favoured but I'm not sure how this could be done short of collecting the chemical... are there any convenient sources of polarised light in space?

Re: Not necessarily a single enantiomer

[Anonymous Coward]

Well you're a 50/50/50 ratio of stupid! Hah, how do you like that!

Re:Not necessarily a single enantiomer

[Anonymous Coward]

They look at light coming from the source. If there is any chirality, then the light is polarized into one plane and that plane is rotated 90 degrees left or right to the direction of the light.

"In 1813 Jean Baptiste Biot noticed that plane-polarized light was rotated either to the right or the left when it passed through single crystals of quartz or aqueous solutions of tartaric acid or sugar. Because they interact with light, substances that can rotate plane-polarized light are said to be optically active. Those that rotate the plane clockwise (to the right) are said to be dextrorotatory (from the Latin dexter, "right"). Those that rotate the plane counterclockwise (to the left) are called levorotatory (from the Latin laevus, "left"). "

http://chemed.chem.purdue.edu/genchem/topicreview/bp/1organic/chirality.html

Re:Not necessarily a single enantiomer

[koreanbabykilla]

TFA was not that long....
The complex signals tied to propylene oxide were not precise enough for the researchers to determine whether the molecules were orientated to the left or to the right.

Like a hand's shadow, "it's impossible to tell if the left or the right hand is casting the shadow," said California Institute of Technology chemistry graduate student Brandon Carroll.

Re:Not necessarily a single enantiomer

[Anonymous Coward]

We have a non 50:50 ratio for left-handed aminoacids found in non-earthly bodies:
http://www.nasa.gov/topics/solarsystem/features/life-turned-left.html

It was not collected "in space" nor seen in the center of the galaxy, so there's that.

Re: Cause and Effect

[Anonymous Coward]

You did see this part right?
"in a giant cloud of gas and dust near the center of the Milky Way galaxy. "

Re: Cause and Effect

[Anonymous Coward]

Yes, advanced alien civilizations.
BTW, radioastronomer here, just kidding. But which telescope was used to perform the observations is not mentioned.

Drake's equation

[SciCom Luke]

So Drake was right after all. There is life everywhere.

Re:Drake's equation

[JaredOfEuropa]

No, there are molecules everywhere...

Re:Drake's equation

[Anonymous Coward]

mah, life's a pretty arbitrary division between 'collections of molecules which aren't alive' and 'collections of molecules which are alive'

Re:Drake's equation

[Anonymous Coward]

Is there even a division? Life is at it simplest level -if there is a one- an interaction of non-alive molecules compounded and compounded until they behave in an organized way. Or not...

Wonder

[Anonymous Coward]

if there are songs in the key of life out there.

Any one?

Re: Wonder

[Anonymous Coward]

That would be every song ever.

That's a long way

[Hognoxious]

It's gone a long way in 6000 years.

Re:That's a long way

[Empiric]

Jesus said, "It is to those who are worthy of my mysteries that I tell my mysteries. Do not let your left (hand) know what your right (hand) is doing."

--Thomas

Nothing to see here

[sugar and acid]

They've found that one of the simplest pair of chiral molecules can be created in space. Not surprising, and both the left and right enantiomers (the left and right handed molecules) are almost certainly present in a 50/50 ratio, so not enantiomerically pure. They have not shown anything at all interesting here.

One of the defining things about chiral chemistry is that to have a pure enantiomeric compound you either have to start with an enantiomerically pure compound as a starting materials (biologically derived materials are the only known natural source) or have it interact with another enantiomericially pure catalyst (biological enzymes being the only known natural source of these) or purification medium. It is pretty much a signature of biology.

  What would be interesting is if there was found a chiral molecule in space that was significantly biased to one enantiomer. Depending on the context of what was found this would be proof of either extraterrestrial life, or a cosmic enantiomeric enrichment process that would have huge implications for understanding the origin of life.

Re:Nothing to see here

[Dcnjoe60]

What would be interesting is if there was found a chiral molecule in space that was significantly biased to one enantiomer. Depending on the context of what was found this would be proof of either extraterrestrial life, or a cosmic enantiomeric enrichment process that would have huge implications for understanding the origin of life.

It would most certainly not be proof of either extraterrestrial life. It would only prove that there is some process going on in space producing a biased enantiomer. Could life be the process doing it? Yes, but unless we are claiming to know everything that occurs at the center of the galaxy where these enantiomers have been found, it would not be scientifically valid to claim it as proof of life.

As for an enantiomeric enrichment process and the implication for understanding the origin of life, that too is pretty far fetched. It could help explain why there is a bias such as the immense gravitational fields, or heat or radiation or any number of things known and unknown. But, whatever that cause is, it would need to be determined if the bias had been the other way, would it had prohibited the formation of life? In otherwords, do all of our enantiomer exist in their current direction because the other direction would not be conducive to life (as we know it) or do they exist in their current direction because they are just made up of what happened to be the dominant version?

If the answer of that question is the former, then there may be huge implications for understanding the origin of life. But only if we could determine what caused the bias in the beginning and whether or not that force still exists or the bias seen now is just an artifact (replicating molecules tend to replicate in the same pattern).

Re:Nothing to see here

[Anonymous Coward]

One of the defining things about chiral chemistry is that to have a pure enantiomeric compound you either have to start with an enantiomerically pure compound as a starting materials (biologically derived materials are the only known natural source) or have it interact with another enantiomericially pure catalyst (biological enzymes being the only known natural source of these) or purification medium. It is pretty much a signature of biology.

Or the result of photochemistry done with circularly polarized light... something stars emit a fair amount of. So no, not an exclusive signature of life.

Re:Nothing to see here

[Anonymous Coward]

did you just take three paragraphs to say the exact same thing GP said in one sentence?

Depending on the context of what was found this would be proof of either extraterrestrial life, or a cosmic enantiomeric enrichment process that would have huge implications for understanding the origin of life.

You must be a social science major.

Re:Nothing to see here

[sugar and acid]

Or the result of photochemistry done with circularly polarized light... something stars emit a fair amount of. So no, not an exclusive signature of life.

That would be a cosmic process for enriching enantiomers. Which would have implications for the origin of life, as life has chosen specific enantiomers. Read my last sentence:)

In truth the CPL light theory for enantiomeric enrichment is far fetched. It is the effect of the opposite signed circular dichroism (differential absorbance of circular polarised light) of the 2 enantiomeric forms, and that is ~1x10^-5 for the vast majority of chiral molecules compared to the overall absorbance. All the material would be destroyed before any meaningful enrichment occurred.

I think the real answer is that life just started, and a choice had to be made. All biochemistry would work perfectly in the complete mirror image if the universe had chosen that way round, but to replicate and reach enough complexity one enantiomeric form for all the complex carbon molecules had to be chosen.

Interesting from another aspect

[robi5]

The news is interesting not so much for its contents, but for its illumination of a gap in my knowledge. I'm nowhere near astronomy, so I didn't know that in the past we were _not_ aware of the presence of asymmetric molecules in space. If someone asked, I'd have responded, "sure there are probably asymmetric molecules in space, why not" so in some sense, I might have given a more correct answer than someone who knew more about space. The downside is that when you not only learn from a piece of news, but it highlights a gap in your understanding before, then it's quite humbling. It's a bit like waking up in Vegas, and you're told you divorced while you were drunk, yet you aren't aware of getting married in the first place.

Re:Interesting from another aspect

[TheMadTopher]

It's a bit like waking up in Vegas, and you're told you divorced while you were drunk, yet you aren't aware of getting married in the first place.

Oh no, not another one of those nights....

Origin of life? Man, how about the origin of what the hell happened last night?

Chirality - Wikipedia, the free encyclopedia

[Anonymous Coward]

Since we prefer a better explanation of Chirality.

Re:Chirality - Wikipedia, the free encyclopedia

[Anonymous Coward]

I learned everything I need to know about Chirality from watching Breaking Bad episode 1.

Re:Cause and Effect

[Thanshin]

One day, the "Most Stupid Comment of the Day!" award will remain non-awarded.

Thanks to you, this won't be the day.

Why should chirality is be considered strange?

[140Mandak262Jamuna]

From freshman chemistry class I keep hearing this "mirror image" molecules, and only one form is found in anything biological and it is very strange. As far as chemical reactions go, both left handed and right handed forms work equally well. I even remember a puzzler from Discover magazine, where the answer was, "take a biopsy sample of the alleged alien life form and check if it is the right handed or left handed version of the molecule. 50% chance you will get a definite answer".

While biologists are finding this property perplexing and strange, in the same freshman year, the physics prof started electro magnetics class with Biot-Savart law. Basically electric currents going around in a loop create a magnetic field using right-hand-thumb rule: Make a thumbs up sign with your right hand, current goes along the fingers and the mag field is along the thumb. Never wondered why it is right hand thumb rule, and not the left hand thumb rule. Never philosophized why electro magnetics in our universe is following the right hand thumb rule. No Discover mag puzzler with the solution, "Check the Biot-Savart law. If the mag field of that coil is following left handed thumb rule, it is 100% certain that worm hole has transported you to a different universe".

Re: Why should chirality is be considered strange?

[Anonymous Coward]

The right hand rules in electromagnetism isn't a fundamental property of the universe, but just a result of sign convention. If we had a signed positive charge to electrons and flipped the definition of current, you would end up with a left hand rule. If we had picked the opposite definition of what the positive direction of the magnetic field means , we would have left hand rules. You can make the vector cross product left handed instead of right handed, and physics is fundamentally the same with some sign flips in definitions that are arbitrary human notation.

Re: Why should chirality is be considered strange?

[Arnold Reinhold]

The right hand rules in electromagnetism isn't a fundamental property of the universe, but just a result of sign convention. If we had a signed positive charge to electrons and flipped the definition of current, you would end up with a left hand rule. If we had picked the opposite definition of what the positive direction of the magnetic field means , we would have left hand rules. You can make the vector cross product left handed instead of right handed, and physics is fundamentally the same with some sign flips in definitions that are arbitrary human notation.

Correct. But non-conservation of parity in the weak interaction does produce chirality. However it is not clear how this property of sub-atomic particles could bias chemical reactions to favor one handedness over the other. More likely chirality in biology reflects a "first mover advantage" in early evolution. Descendants of a self-replicating molecule that happened to form in one chirality may simply have come to dominate life. Another explanation is that life did not evolve on Earth and was seeded by a single chiral bacteria.

Re: Why should chirality is be considered strange?

[Gilgaron]

First mover advantage probably has it: since all of the amino acids are made from one another, they're going to match up with whatever they were made from. I would guess that before the last common ancestor there may be have been some other primitive organisms with left handed amino acids, but whichever got slightly bigger faster would have the advantage of a primitive ecology and then swamp out the other after some natural selection feedback loops improved things.

Re: Why should chirality is be considered strange?

[Anonymous Coward]

I was reading some discussion yesterday about how a three dimensional body traveling along a path under gravitational influence could, by rotationally twisting and redistributing some mass, alter its trajectory slightly. Perhaps a certain effect obtained by chiral molecules gave them some kind of advantage in this regard. Possibly the handedness is an artifact of the rotation and orbital velocity of the earth? Kind of out on a limb with that but , eh, it's slashdot.

Re: Why should chirality is be considered strange?

[140Mandak262Jamuna]

No. It is not a matter of sign convention. Some charge of some polarity is moving in some direction. It induces force in one direction and not its reverse direction. That is true in this universe. We assigned some convention for polarity and it results in right hand rule, and a different convention will produce left hand rule. But the fact remains, it will always be a left hand rule or right hand rule based on our definition of left right positive and negative charges. Whatever rule we end up with, we have no explanation why the "other handed" rule is not true, nor do we know if there are other universes where the other handed rule could be true.

Don't even get me started on the concept of lateral inversion in the mirror images. A mirror on vertical plane produces a laterally inverted image. OK. Why it does not produce upside down image? Is it in our brain? A mirror on horizontal plane, like a lake surface, produces an upside down and laterally inverted image. Why?

Re: Why should chirality is be considered strange?

[dcollins117]

A mirror on vertical plane produces a laterally inverted image. OK. Why it does not produce upside down image? Is it in our brain? A mirror on horizontal plane, like a lake surface, produces an upside down and laterally inverted image. Why?

Richard Feynman explains it best. Watch it here.

Re: Why should chirality is be considered strange?

[Anonymous Coward]

Some charge of some polarity is moving in some direction.

And that depends on the magnetic field present, for which is highly dependent on local conditions, not some fundamental constant of the universe. This has nothing to do with whether we have a left or right hand rule, because you end up with a mix. Which is why you can get both circular polarizations from emissions of a star depending on the situation...

But the fact remains, it will always be a left hand rule or right hand rule based on our definition of left right positive and negative charges.

And definition of current and handedness of the coordinate system. There are multiple right hand rules in physics and it is easy enough to have a mix of left and right handled rules depending on your definition.

The stereoselectiveness of nature is no mystery

[Anonymous Coward]

The evolution of enzymes necessitates stereoselectiveness, the only other option is two enzymes for every reaction - which is too costly, unlikely and unnecessary.

Beware the protomolecule!

[swb]

Has anyone else read the Expanse series and thought of the protomolecule when they read this?

What?

[Anonymous Coward]

I thought to explore space we had to send test pilots in rubber suits in person?

The conclusions

[Anonymous Coward]

The discovery of propylene oxide in space boosts theories that chirality has cosmic origins.

Yes, the natural conclusion indeed is that it must have been originated from interstellar cloud from which they ended right to Earth rather than other more significant gravity wells in the solar system. The conclusion that molecular clouds could have conditions where those could have formed like on earths Hadean period are obviously invalid and the conditions in said molecular cloud tells nothing that was going on in Earths atmosphere/oceans.

The above paragraph was obviously sarcastic one.

right-handed forms

[lskovlund]

One has to be careful with wording. Dextrorotatory ("right-handed") forms of various amino acids do occur in various roles in living organisms, just not commonly in protein synthesis.
http://www.ncbi.nlm.nih.gov/pm...
http://www.ncbi.nlm.nih.gov/pm...

Chirality probably didn't come from space

[LeDopore]

TFA suggests a beautiful idea: that life bears the imprint of handedness derived from cosmic dust. The idea may be beautiful, but it's wrong. It's much more likely that the chirality of biomolecules we see on Earth came from spontaneous symmetry breaking on Earth itself than by space seeding any preferred chirality.

Complex molecules in living beings are assembled from consistent smaller molecules, known as monomers. Some of these monomers have a handedness (they have two enantiomers), and in that case living things will almost always use just one of the enantiomers. The best explanation for why living things tend to use just one enantiomer is the same reason you would hate to have two slightly different kinds of Lego blocks with incompatible pitch: this diversity usually just gets in the way of assembling complex macromolecules without providing any compelling value.

Thus, we know even given no seeding of chirality from space, life would pick one chirality since having just one is usually useful. Add to that the facts that we haven't yet found a non-racemic mixture of anything in space, and that even if we did the fraction of space-derived non-racemic molecules on the Earth's surface would hardly noticeably change the balance of chiralities found in proto-life Earth, and it's pretty clear that the chirality of biomolecules in living things is totally independent of biased enantiomers from space.
 

Re:Chirality probably didn't come from space

[Gilgaron]

Excellent explanation! I've had trouble explaining this before, but the Lego explanation should have legs with lay people.

Re:Chirality probably didn't come from space

[thrich81]

There have been theories for some years that explain the preferred chirality of biological molecules (the ones which are chiral) because of the inherent asymmetry of the weak nuclear force. I've seen arguments that because of the weak force one enantiomer of a chiral molecule will be very slightly more tightly bound than the other and then due to biological selection (as you describe) and amplifying feedback effects during the rise of the first set biological molecules that the chirality we see today was preferred and not randomly selected. One quick recent reference: http://www.nature.com/news/for...

Re:Chirality probably didn't come from space

[LeDopore]

I've seen this work too, and I don't buy it. The effects are far too subtle to influence chemistry enough for life to care. Once one chirality started getting used by an early microbe, there's no compelling reason to start experimenting with the other, and the chances that the weak force's minuscule influence had any significant influence on which enantiomer was chosen are pretty much nil.

Re: Cause and Effect

[Anonymous Coward]

Parkes Telescope, Australia.

You're welcome.

Re: Cause and Effect

[Anonymous Coward]

It was a radio telescope, I'm pretty sure. Are you new to this?

Just kidding.

Re:Cause and Effect

[Applehu Akbar]

"Of course these chemicals are now in space. Look at all the things we've launched into it! Undoubtedly these little things just hopped along for the ride."

Oh look, it's Space Nutter Troll once again demonstrating how little he knows about science.

Re: Cause and Effect

[Anonymous Coward]

http://www.news.com.au/technology/science/space/csiros-parkes-telescope-detects-key-feature-of-life-outside-our-solar-system/news-story/4609a1e78a047b159c237e4deaa80776

Re:Cause and Effect

[Anonymous Coward]

Well, as long as at least one comment is posted in a day, there will be a most stupid comment. (If only one comment is posted, it will also be the smartest comment. And if multiple comments are equally stupid they can get to share the award.)

So you get to share equal credit for that.

Chirality comes from Scattering

[Anonymous Coward]

"Right hand" and "Left Hand" chirality is named for the polarization of electromagnetic radiation scattered from the molecule. If there is a primordial goo of substances that happen to form a chiral molecule, it is because that goo was in the presence of a right hand or left hand circular polarized incident field. Because, you know, field and wave scattering is reciprocal.

There are many sources of circularly polarized fields and waves in the cosmos. These waves can couple into primordial goo, and the incident energy can create more organized molecules.

Pretty simple...

Right-handed or left ...

[fahrbot-bot]

Scientists have long pondered why living things make use of only one version of certain molecules, such as the 'right-handed' form of the sugar ribose, which is the backbone of DNA.

The left-handed version of the sugar ribose (and other things) is used in the mirror universe where the evil versions of ourselves are - Kirk and Dr. McCoy know what I'm talking about.

Re:In fact ...

[Anonymous Coward]

Someone's brainwashed..

Philosopy

[waTeim]

Does this mean that the yin-yang symbol must be drawn slightly differently?