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Author Topic:   The Recurrent Problem of Chirality
Evopeach
Member (Idle past 6731 days)
Posts: 224
From: Stroud, OK USA
Joined: 08-03-2005


Message 1 of 81 (285281)
02-09-2006 4:49 PM


Life as we know it, uses twenty amino acids to form the molecules that enable life to operate biologically, whether plant or animal, macroscopic or microscopic.
These forms are except for one extant in nature in two, three-dimensional forms called levo and dextro, left and right handed as in a glove analogy.
Now when these two forms make their way into biological molecules used in life they appear in completely separated form and not in mixed forms of both types.
Life cannnot begin or proceed using racemic mixtures of the two forms for life molecules.
Now the evolution of the first replicator pre-rna to rna to dna and the first cell could not have happened without this separation of otherwise identical forms of the molecules.
More importantly perhaps is the fact that it is only the three dimensional aspect of the molecules and their coiled shape in the double helix of the DNA that enables them to store the information contained in the "genetic code" sequences non-linearly rather than linearly in two dimensions. In fact it is impossible to store the information in three dimensions in the double helix form using racemic mixtures of molecules.. it simply cannot be done.
The microscopic sized 3-d information storage and retrieval capacity of the DNA molecule critical to the entirity of celluar operations is dependnet on the optical purity of the building block molecules of life.
But since the two forms are chemically identical and have identical entropy states they cannot be separated or distinguished by pure chemistry. There is no entropy or alternately free energy gradient.
Now more than 100 years ago a brilliant European chemist discovered that if he could take a molecular extract from the deadly nightshade plant the l-brusine built by the genetic code of deadly nightshade in its cell and use it in a carefully controlled experiment with the tetrahedral molecule alanine in both L& D forms and centrifuge the mixture he could obtain a separation because the l-form salt would percipitate out as a pure crystal (valanine) while the d form stayed in solution as a brown oily substance.
But it was only possible by using the dna information in the deadly nightshade which makes the l-brusine as part of its celluar operations that this optically pure separation of the alinine forms was possible.
But of course never not ever nanda did such a possibility exist in the pre-rna rna world so how did the separation occur which is absolutly required for 3-d data storage on the DNA molecule... not one feasable theory or experiemnt has ever been been proposed much less performed and demonstrated.
Another demonstration of intelligent design.. inexplicable by evolutionary theory.

Replies to this message:
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Evopeach
Member (Idle past 6731 days)
Posts: 224
From: Stroud, OK USA
Joined: 08-03-2005


Message 6 of 81 (285690)
02-10-2006 5:05 PM
Reply to: Message 5 by jar
02-10-2006 1:17 PM


Re: on sources of Chirality
Purdue article is typically silly and humerous. The molecule in question is not even necessary for the mammalian diet since it can be synthesized easily within the body from other molecules. That would selectively make it a late comer not a dominate first comer.
The verbage in the paper is replete with the typical meybe, we imagine, could have been phrases typical of the evolutionary communities vain imaginings. LOL
Not a scintilla of text is devoted as to why or how one molecules predisposition to bond with lefthanded molecules arose is given or how that could possibly influence what other molecules predisposition might be particularly whrn the so called dominate leader doesn't even apprear in the great majority of proteins and enzymes.
Neither does the paper address how among the 50/50 mixture of racemates across all the amino acids present in any abiotic sea and there are many how only twenty are exclusively used in life and of course only the optically pure separated forms are used.
I believe I'll pass on the spaceman from planet zabot theory.. only to say that when these sci-fi theories are proposed its out of desperation because no terrestrial theories such as one are anything other than laughable.
Rock terrraces show 10% bias to lefties... well is 10% the same as 99.99999...999% separation because thats whats required for polypeptides in life molecules. And even if true that lefties like terraces.. why one cannot even imagine ... the end result requires the chance formation pulr lefty molecules when there were plenty of righties absolutely therodynamically indistinguishable handy on the same terrace.... 40% of the molecules were right handed.. maybe they were ugly. LOL
"parity-violating energy differences" could be amplified kinetically in the pre-biotic soup to preferentially select today's L-amino acid/D-sugar biochemistry over D-amino acid/L-sugar "mirror life".
If this newspeak can be interpreted to make any sense.. lets hear it.
Of course any so called energy difference at the QM level would need be amplified say by a factor of a trillion orders of magnitude. But I geuss the magnifier got lost because today no experiment can demonstrate its operation. Yep those 50/50 racemic mixtures just refuse to be amplified in the old soup and continue to form useless racemic peptides.
Although we do not fully understand the origin of the chart of intermediary metabolism,our present knowledge points to a logic which I believe we will one day understand as we nowcomprehend structures like the periodic table of the elements.
One day we will all be engulfed in peace and happiness blah blah blah.
The problem of selecting twenty amino acids from many and using only one form predominately remains as inexplicable as 100 years ago.
Separation always requires the genetic machinery codes and instructions that are built in the same optically pure fashion.

This message is a reply to:
 Message 5 by jar, posted 02-10-2006 1:17 PM jar has replied

Replies to this message:
 Message 7 by jar, posted 02-10-2006 5:19 PM Evopeach has replied

  
Evopeach
Member (Idle past 6731 days)
Posts: 224
From: Stroud, OK USA
Joined: 08-03-2005


Message 8 of 81 (285693)
02-10-2006 5:25 PM
Reply to: Message 7 by jar
02-10-2006 5:19 PM


Re: on sources of Chirality
Nice try that argument from credulity..
Actually its an argument from 100 years of abject failure to resolve a major problem which no one has even come close to explaining by evolutionary mechanisms.
The examples you give are five mutually exclusive diametrically opposed pseudo explanations given mostly out of desperation.
They left out the Von Damian Chariot of the Gods theory.
These just so stories without a scintilla of evidence doesn't fly with we true intellects.
Back to the drawing board ... laughable.

This message is a reply to:
 Message 7 by jar, posted 02-10-2006 5:19 PM jar has not replied

Replies to this message:
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 Message 13 by Parasomnium, posted 02-15-2006 4:05 AM Evopeach has not replied

  
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