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Author Topic:   Abiogenesis - Or Better Living Through Chemistry
DNAunion
Inactive Member


Message 76 of 85 (67864)
11-19-2003 10:33 PM
Reply to: Message 75 by MarkAustin
11-18-2003 9:29 AM


Re: Chirality
quote:
DNAunion No, Your original reply said:

--------------------------------------------------------------------------------
The calculation implicitly relies upon homochirality. If both enantiomeric forms of the bases (actually, the sugar moieties of the bases) were present, enantiomeric cross inhibition would hinder the formation of long polymers needed for replication or other complex function.
--------------------------------------------------------------------------------

This clearly states that if both bases were present, the formation of self-replicators would be hindered.


Close enough…

quote:
Rrhain's post clearly demonstrated that relatively simply molecules can selectively extract compounds of the correct chirality. Thus chirality is not a problem in the gross sense.

No, Rei’s post didn’t show that.

For example, saying “relatively simple molecules” is misleading. It was one type of molecule, not a group of different types of molecules (as your wording suggests); the molecule was a 32-amino acid peptide, with a very specific sequence, synthesized with L-enantiomers exclusively, and was the product of rational engineering (it is not a natural peptide; it is a modified version), and it could not do anything - like "self-replicating" or maintaining homochirality as in the experiment - without the researchers intentionally synthesizing and feeding the specific 17-aa and 15-aa “halves”, which also had to be preactivated.

And as I pointed out earlier, Rrhain’s article deals with peptides, whereas my statement dealt with nucleic acids. Anyone familiar with biochemistry knows that those are two very different things.

So no, Rrhain's offered article did not show that having racemic mixtures of nucleotides wouldn't be a problem for the calculation I addressed.

[This message has been edited by DNAunion, 11-19-2003]


This message is a reply to:
 Message 75 by MarkAustin, posted 11-18-2003 9:29 AM MarkAustin has not yet responded

  
DNAunion
Inactive Member


Message 77 of 85 (69882)
11-29-2003 2:50 PM
Reply to: Message 27 by Quetzal
03-01-2002 3:33 AM


quote:
John Paul: Life isn't just about chemical reactions. How long is it going to take before you realize that?

quote:
Quetzal: It most assuredly IS about chemical reactions. When will YOU realize that?

Life isn't just about chemical reactions; for example, it's also about information processing.


This message is a reply to:
 Message 27 by Quetzal, posted 03-01-2002 3:33 AM Quetzal has not yet responded

Replies to this message:
 Message 79 by NosyNed, posted 11-29-2003 3:14 PM DNAunion has responded

  
DNAunion
Inactive Member


Message 78 of 85 (69886)
11-29-2003 3:10 PM
Reply to: Message 57 by DNAunion
11-04-2003 12:22 AM


Re: sadistics
quote:
Rei: there are countless possibilities (I could equally, say, go into the SunY self-replicator, the hexanucleotide self-replicator, Eckland's RNA polymerase self replicator, etc).

quote:
/*DNAunion*/ But since you have asserted as fact that the SunY ribozyme and Eckland's RNA polymerase are self-replicators, you have a position to back up. So you now need to post quotes from the papers for the experiments that show those molecules actually self-replicate.

Rei, do you ever intend to support your assertion?


This message is a reply to:
 Message 57 by DNAunion, posted 11-04-2003 12:22 AM DNAunion has responded

Replies to this message:
 Message 82 by DNAunion, posted 12-14-2003 7:55 PM DNAunion has not yet responded

  
DNAunion
Inactive Member


Message 80 of 85 (69888)
11-29-2003 3:16 PM
Reply to: Message 65 by DNAunion
11-08-2003 12:56 AM


Re: sadistics
quote:
Rrhain: You claim that X is not seen. When shown an example of X, you then claim that it isn't an example of Y and hope to high heaven that nobody notices that you didn't ask for Y in the first place.

quote:
DNAunion: Now who’s playing games! Why the use of variables instead of actual words? So tell us, exactly what did I claim is not seen? Exactly what example of that did you present? Exactly what did I supposedly change the requirement into in order to avoid being shown to be wrong?

Rrhain, do you ever intend to support your assertion? Or should we all just conclude you were being dishonest?


This message is a reply to:
 Message 65 by DNAunion, posted 11-08-2003 12:56 AM DNAunion has not yet responded

  
DNAunion
Inactive Member


Message 81 of 85 (69892)
11-29-2003 3:35 PM
Reply to: Message 79 by NosyNed
11-29-2003 3:14 PM


quote:
And how is that information processed? Is there any chemistry involved in a synapse?

Synapses? As in neuronal connections? What do they have to do with the origin of life? Or are you a closet IDist? :-)

Information in the biological sense I was using involves symbol sequences, such as base sequences in nucleic acids. These symbol sequences serve as an informational template for the production of "offspring" (and in cellular life, for the production of cellular constituents). It is not just the chemistry of the monomers that conveys the information; the sequence of the monomers is of paramount importance. This can be likened to the English language where individual letters are analogous to individual monomers. It is not that an individual letter of the alphabet carries inherent meaning, but a group of them arranged in a specific sequence does. For example, if I took all of the letters in this sentence or post and scrambled them up, the information (both syntactic and semantic) would be lost, even though the same "monomers" would be present in the same quantities.

No experiment to date has demonstrated that undirected, non-biological chemistry alone can generate biological information of the kind needed for a "simple" RNA self-replicator. There is more to life than just chemistry; there is also information processing.

[This message has been edited by DNAunion, 11-29-2003]


This message is a reply to:
 Message 79 by NosyNed, posted 11-29-2003 3:14 PM NosyNed has not yet responded

  
DNAunion
Inactive Member


Message 82 of 85 (72871)
12-14-2003 7:55 PM
Reply to: Message 78 by DNAunion
11-29-2003 3:10 PM


Re: sadistics
Hmmm, I guess I'll have to ask again.

quote:
Rei: there are countless possibilities (I could equally, say, go into the SunY self-replicator, the hexanucleotide self-replicator, Eckland's RNA polymerase self replicator, etc).

quote:
/*DNAunion*/ But since you have asserted as fact that the SunY ribozyme and Eckland's RNA polymerase are self-replicators, you have a position to back up. So you now need to post quotes from the papers for the experiments that show those molecules actually self-replicate.

Rei, do you ever intend to support your assertion?


This message is a reply to:
 Message 78 by DNAunion, posted 11-29-2003 3:10 PM DNAunion has not yet responded

Replies to this message:
 Message 83 by Rei, posted 12-15-2003 4:09 AM DNAunion has responded

  
DNAunion
Inactive Member


Message 84 of 85 (72980)
12-15-2003 1:46 PM
Reply to: Message 83 by Rei
12-15-2003 4:09 AM


Re: sadistics
I fail to see how that supports your assertions in the least.

This message is a reply to:
 Message 83 by Rei, posted 12-15-2003 4:09 AM Rei has not yet responded

  
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