Implications of life being found or not found on Europa

[1oldman2]

it is completely irrelevant after 100 meters

Thanks for the info, that would make a big difference.

 

[1oldman2]

http://www.kiss.caltech.edu/new_website/workshops/life/life.html
http://www.kiss.caltech.edu/study/life/presentations/Hud.pdf
The pdf is interesting and relative to certain post on this thread.

 

[1oldman2]

Seems more common than we thought.
http://www.space.com/33193-organic-molecule-planet-forming-disk.html
http://www.space.com/33167-twisty-chiral-molecule-first-found-interstellar-space.html

 

[Buzz Bloom]

http://www.space.com/33167-twisty-chiral-molecule-first-found-interstellar-space.html

Hi @1oldman2:

I found the articles you cited quite interesting. I found one statement in the article whose link I quoted above which "technically" contradicts something I have recent read in:

Genesis by Robert M. Hazen, p. 181.​

Quote from link (highlighting is mine):

Though the molecules are made of the same components, it's impossible to flip one around to make it exactly match the other.​

Quote from Genesis:

Glenn's research exploited the fact that although almost all of life's amino acids are left handed, as soon as an organism dies , a slow, inexorable process called racemization -- the random flipping of molecules from L to D and vice versa -- begins. Eventually, after a few tens of thousands of years an organism's amino acids will have completely randomized to a 50:50 mixture.​

Regards,
Buzz

 

[1oldman2]

Hi Buzz,
I'm not familiar with "Genesis" however I'm searching for a copy and if I'm $14.00 in the clear when the bills are paid this month I'll likely get the pdf version, looks like a very interesting read. I'm always a little suspicious of reading "breakthrough announcements" in everyday publications and it seems the one I posted was based on http://science.sciencemag.org/content/352/6292/1449 . Guess I'll have to wait and see what becomes of the contradiction. If you find anymore on this particular subject please let me know.
Thanks,

 

[Buzz Bloom]

Hi @1oldman2:

I first became interested in the origin of life when I read

English translation: Oparin, A. I. The Origin of Life. New York: Dover (1952)​

as a teenager. Since then I have read several other books on this topic, but Genesis by Hazen (2005) has become my new favorite. It is mostly a very well written autobiographical description of many laboratory experiments he and others conducted to confirm ideas about various mechanisms involved in the origin of life.

Hope you are able to get a copy. Have you investigated library resources? The copy I read was from my local town library.

Regards,
Buzz

 

[1oldman2]

Have you investigated library resources? The copy I read was from my local town library.

great suggestion, I tend to under use the local library.

 

[Ygggdrasil]

Quote from link (highlighting is mine):

Though the molecules are made of the same components, it's impossible to flip one around to make it exactly match the other.​

Quote from Genesis:

Glenn's research exploited the fact that although almost all of life's amino acids are left handed, as soon as an organism dies , a slow, inexorable process called racemization -- the random flipping of molecules from L to D and vice versa -- begins. Eventually, after a few tens of thousands of years an organism's amino acids will have completely randomized to a 50:50 mixture.​

​

These statements are both accurate and the confusion comes from the different uses of the word "flip."

The statement from the link is essentially the definition of chiratlity: molecules that cannot be superposed on their mirror images through simply rotating the molecule (i.e. "flipping the molecule around").

The Genesis quote is referring to a set of chemical reactions that can "flip" or randomize the stereochemistry of chiral molecules (often by first converting them to an achiral intermediate. An example of such a reaction is one involving the an SN1 mechanism. Because racemization involves more than just simply rotating the molecule, molecules that can undergo racemization are still considered chiral.

 

[Buzz Bloom]

The statement from the link is essentially the definition of chiratlity: molecules that cannot be superposed on their mirror images through simply rotating the molecule (i.e. "flipping the molecule around").

Hi: @Ygggdrasil:

Thank you very much for correcting my misunderstanding.

Regards,
Buzz

 

[1oldman2]

Regarding the last few posts, Thanks for the info, this site is great at clearing up misunderstandings.