[quote]The largest noncyclic molecules detected in the interstellar medium (ISM) are organic with a straight-chain carbon backbone. We report an interstellar detection of a branched alkyl molecule, iso-propyl cyanide (i-C3H7CN), with an abundance 0.4 times that of its straight-chain structural isomer. This detection suggests that branched carbon-chain molecules may be generally abundant in the ISM.[/quote]
[quote]The formation of branched molecules is important, given the analogous structure of familiar amino acids — some of the building blocks for life.[/quote]
source: [url]http://www.sciencemag.org/content/345/6204/1584[/url]
Basically they found amino acids in space. If anybody happens to have sciencemag access feel free to PM some quotes of it to me so i can shove it on this.
edit: basically they found stuff
IIRC, amino acids form automatically in the right chemical conditions, which were present when the Earth was forming. Finding them in the interstellar medium suggests that there is an abundance of places in the galaxy which chemically resemble pre-life Earth.
[QUOTE=Sega Saturn;46093723]IIRC, amino acids form automatically in the right chemical conditions, which were present when the Earth was forming. Finding them in the interstellar medium suggests that there is an abundance of places in the galaxy which chemically resemble pre-life Earth.[/QUOTE]
so basically actual evidence that life could have formed on other planets besides what is purely theoretical, right?
[QUOTE=finbe;46093696]source: [URL]http://www.sciencemag.org/content/345/6204/1584[/URL]
Basically they found amino acids in space. If anybody happens to have sciencemag access feel free to PM some quotes of it to me so i can shove it on this.[/QUOTE]
No. They haven't found amino acids. They merely found a branched nitrile. However, the presence of a functional group on a molecule in a position other than the end bodes well for finding an actual branched chain amino acid.
[QUOTE=Sega Saturn;46093723]IIRC, amino acids form automatically in the right chemical conditions, which were present when the Earth was forming. Finding them in the interstellar medium suggests that there is an abundance of places in the galaxy which chemically resemble pre-life Earth.[/QUOTE]
I doubt it. Interstellar reactions occur at ridiculously low pressures and at extreme temperatures. Under these conditions most reactions are catalysed by high energy cosmic rays or by UV radiation from nearby stars, neither of which really exist on Earth (and thankfully so, or we'd all be puddles of simple molecules by now).
This is just more and more evidence to point towards the fact that life could exist elsewhere in the universe.
We see all of these building blocks of life, in almost every crevasse we look.
How did we manage to observe what molecules are in the interstellar medium?
[QUOTE=Krinkels;46093877]How did we manage to observe what molecules are in the interstellar medium?[/QUOTE]
Spectroscopy.
[QUOTE=Krinkels;46093877]How did we manage to observe what molecules are in the interstellar medium?[/QUOTE]
When light passes through a substance it leaves a mark depending on the substance. That's my shitty definition of spectroscopy but here's a picture. Take a look
[IMG]http://www.astro.rug.nl/~ndouglas/teaching/IMAGES/achilles.elements.gif[/IMG]
Unrelated to the above but I'm curious about these amino acids.
Specifically are they "left-handed" amino acids? If not then there is nothing to get hyped about.
[QUOTE=MillySoose;46094027]When light passes through a substance it leaves a mark depending on the substance. That's my shitty definition of spectroscopy but here's a picture. Take a look
[IMG]http://www.astro.rug.nl/~ndouglas/teaching/IMAGES/achilles.elements.gif[/IMG]
Unrelated to the above but I'm curious about these amino acids.
Specifically are they "left-handed" amino acids? If not then there is nothing to get hyped about.[/QUOTE]
Because life is impossible without left handed amino acids...
The chemistry of left and right handed amino acids is identical as long as you swap the chirality of all amino acids, enzymes and anything else that they interact with.
[QUOTE=sltungle;46094117]Because life is impossible without left handed amino acids...
The chemistry of left and right handed amino acids is identical as long as you swap the chirality of all amino acids, enzymes and anything else that they interact with.[/QUOTE]
And how could you do that? I don't believe that is possible. If this chirality is irrelevant then why is this a big discovery. We already knew there were amino acids in space.
[QUOTE=MillySoose;46094142]And how could you do that?[/QUOTE]
... nature does it. If right handed amino acids became dominant in a certain environment and life arose from it then the enzymes that formed would work with right handed amino acids simply because any structure that arose to deal with left handed amino acids wouldn't fucking work and thus wouldn't proliferate because any organism containing it would die.
[QUOTE=sltungle;46094161]... nature does it. If right handed amino acids became dominant in a certain environment and life arose from it then the enzymes that formed would work with right handed amino acids simply because any structure that arose to deal with left handed amino acids wouldn't fucking work and thus wouldn't proliferate because any organism containing it would die.[/QUOTE]
This doesn't answer my question. I asked how could you reverse chirality. I didn't ask how right-handed amino acids could form life.
[QUOTE=MillySoose;46094181]This doesn't answer my question. I asked how could you reverse chirality. I didn't ask how right-handed amino acids could form life.[/QUOTE]
I don't think you understand what it is you're asking. When you form amino acids via purely chemical pathways (say in an experiment similar to the Miller-Urey experiment) they form in a 1:1 ratio of left and right handed (baring stochastic events and anything that could bias chirality). Chirality is the defining characteristic that separates right and left handed molecules (which are referred to as enantiomers, or optical isomers).
[QUOTE=sltungle;46094201]I don't think you understand what it is you're asking. When you form amino acids via purely chemical pathways (say in an experiment similar to the Miller-Urey experiment) they form in a 1:1 ratio of left and right handed (baring stochastic events and anything that could bias chirality). Chirality is the defining characteristic that separates right and left handed molecules (which are referred to as enantiomers, or optical isomers).[/QUOTE]
No I understand what I am asking. I also understand that right-handed amino acids should technically be able to form life. So far they haven't and it's not anything new that they exist in space. So our best bet would be to look for left-handed amino acids. My question is how are you going to reverse their chirality in space, with conditions completely unlike the Miller-Urey experiment (which was designed to replicate the conditions of early earth)
Nobody knows why left handed amino acids were selected by life on Earth, but there's absolutely no reason to say that our best bet is to look for left-handed ones.
Do some reading on the topic if you're interested. [URL="http://en.wikipedia.org/wiki/Homochirality#Mirror-symmetry_breaking"]There's some brief info on the wikipedia page of homochirality.[/URL]
[QUOTE=sltungle;46094248]Nobody knows why left handed amino acids were selected by life on Earth, but there's absolutely no reason to say that our best bet is to look for left-handed ones.
Do some reading on the topic if you're interested. [URL="http://en.wikipedia.org/wiki/Homochirality#Mirror-symmetry_breaking"]There's some brief info on the wikipedia page of homochirality.[/URL][/QUOTE]
Our reason is that's its happened once to left-handed amino acids and it's never been demonstrated to have happened to right-handed amino acids. It's the same reason astrobiologists go looking for extra solar planets with water and warm climates. These conditions have been clearly demonstrated to support life. The same goes for left-handed amino acids.
[QUOTE=MillySoose;46094254]Our reason is that's its happened once and it's never been demonstrated to have happened to right-handed amino acids. It's the same reason we go looking for extra solar planets with water and warm climates.[/QUOTE]
Your reasoning is hardly scientific in the least and flies right in the face of discovery and progress.
I don't think life cold form using [I]both[/I] left and right handed amino acids. There'd be no order to the structure of DNA (or any other kind of genetic code that utilised amino acids) if both right and left handed amino acids could be present. Anywhere in the universe where life arises and amino acids play as important a role as they do to life on Earth is bound to find itself operating under [I]either[/I] the hierarchy of left [I]or[/I] right handedness; not both. We [I]can't[/I] observe both here on Earth, so we only got one. We got left. It was a coin toss. Nothing more.
[QUOTE=sltungle;46094267]Your reasoning is hardly scientific in the least and flies right in the face of discovery and progress.
I don't think life cold form using [I]both[/I] left and right handed amino acids. There'd be no order to the structure of DNA (or any other kind of genetic code that utilised amino acids) if both right and left handed amino acids could be present. Anywhere in the universe where life arises and amino acids play as important a role as they do to life on Earth is bound to find itself operating under [I]either[/I] the hierarchy of left [I]or[/I] right handedness; not both. We [I]can't[/I] observe both here on Earth, so we only got one. We got left. It was a coin toss. Nothing more.[/QUOTE]
What is the problem with my reasoning? If we know life exists here on Earth with left-handed amino acids we know that
1. It undoubtedly can exist
2. It does exist
3. It may exist elsewhere
All we can say about right-handed amino acids is
1. It probably can exist
If you're seeking alien life in the cosmos which would you look for?
[QUOTE=MillySoose;46094317]What is the problem with my reasoning? If we know life exists here on Earth with left-handed amino acids we know that
1. It undoubtedly can exist
2. It does exist
3. It may exist elsewhere
All we can say about right-handed amino acids is
1. It probably can exist
[B]If you're seeking alien life in the cosmos which would you look for?[/B][/QUOTE]
Either because I seem to have a better understanding of chemistry than you.
[QUOTE=sltungle;46094330]Either because I seem to have a better understanding of chemistry than you.[/QUOTE]
Either or what? How does this have anything to do with it anyway? What does your knowledge of chemistry have over my reasoning?
[QUOTE=Fourm Shark;46094365]By that same reasoning we should only look for earth sized planets with saltwater oceans and oxygen rich atmospheres if we want to find life.[/QUOTE]
100% of all life bearing planets are named earth
therefore we should only be looking for planets named earth.
[QUOTE=Fourm Shark;46094365]By that same reasoning we should only look for earth sized planets with saltwater oceans and oxygen rich atmospheres if we want to find life.[/QUOTE]
This is exactly what scientists do. They look for quote: "Earth-sized planets" which resemble Earth in as many ways as possible. Maybe you have a better lead?
[QUOTE=finbe;46094373]100% of all life bearing planets are named earth
therefore we should only be looking for planets named earth.[/QUOTE]
The name of our planet has nothing to do with it's habitability or it's sustainability of life. The existence of left-handed amino acids is key to what we have so far observed as organic life.
I took a course specifically on the topic of astro-biology. (As in, the search for life elsewhere, not the biology of said life.) I'm very well oriented with these things.
[QUOTE=Fourm Shark;46094407]-Right handed amino acids could support life
-Find right handed amino acids
???
What kind of point are you trying to make here[/QUOTE]
They don't and have never been demonstrated to support life. Not even here on Earth. Why should we waste our time when we know that left-handed life exists and undoubtedly can exist?
[QUOTE=MillySoose;46094027]When light passes through a substance it leaves a mark depending on the substance. That's my shitty definition of spectroscopy but here's a picture. Take a look
[IMG]http://www.astro.rug.nl/~ndouglas/teaching/IMAGES/achilles.elements.gif[/IMG]
Unrelated to the above but I'm curious about these amino acids.
Specifically are they "left-handed" amino acids? If not then there is nothing to get hyped about.[/QUOTE]
Those are electronic spectra arising from transitions between electronic states though. When detecting these compounds, we use rotational spectroscopy (transitions occur in the microwave spectrum).
On a side note, chirality is indeed irrelevant. As long as the configuration of every single stereocenter in every molecule that is involved in life is flipped, everything should work just fine.
[QUOTE=MillySoose;46094391]
The name of our planet has nothing to do with it's habitability or it's sustainability of life. The existence of left-handed amino acids is key to what we have so far observed as organic life.[/QUOTE]
No, what matters is that they're homologous with other amino acids of which they interact with. sltungle even linked you to the exact section of the wikipedia page on it, read it.
[url]http://en.wikipedia.org/wiki/Homochirality#Mirror-symmetry_breaking[/url]
[QUOTE=finbe;46094425]No, what matters is that they're homologous with other amino acids of which they interact with. sltungle even linked you to the exact section of the wikipedia page on it, read it.
[url]http://en.wikipedia.org/wiki/Homochirality#Mirror-symmetry_breaking[/url][/QUOTE]
No I understand that it is perfectly possible for right-handed amino acids to support life. The point is they haven't and life could be a rare thing with all we know. It's more likely that life elsewhere would be derived from the same left-handed amino acids as us than it would be to have evolved independently from right-handed amino acids.
[QUOTE=Fourm Shark;46094469]kinda a moot point tbh[/QUOTE]
I wouldn't say so. It helps scientists narrow the query of the search for life. For now, for time's sake, since we cannot know if this life exists (only that it is possible for it to exist) it's best to avoid looking for right-handed amino acids in space and focus on other leads.
[QUOTE=MillySoose;46094509]I wouldn't say so. It helps scientists narrow the query of the search for life. For now, for time's sake, since we cannot know if this life exists (only that it is possible for it to exist) it's best to avoid looking for right-handed amino acids in space and focus on other leads.[/QUOTE]
We need to be searching as many possible leads as we can.
"Amino acids detected in the interstellar medium" aka God doesn't use paper towels when masturbating
[QUOTE=MillySoose;46094391]This is exactly what scientists do. They look for quote: "Earth-sized planets" which resemble Earth in as many ways as possible. Maybe you have a better lead?
[...][/QUOTE]
As a matter of fact they don't, at least not any more.
This is because the notion that life is especially likely on Earth-like planets is, while maybe approachable, scientifically silly.
It is so because the sample size it's based on is absolutely tiny and even on this planet there are many "not Earth-like" environments completely overgrown with life.
If someone is specifically looking for Earth-like planets there's a good chance they are fishing for research grants from people with little understanding of actual science or being populists in order to make the subject more approachable or things like that.
Sorry, you need to Log In to post a reply to this thread.
