Re: origin of biological chirality?

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Sujet : Re: origin of biological chirality?
De : nospam (at) *nospam* buzz.off (Bob Casanova)
Groupes : talk.origins
Date : 22. Aug 2024, 15:02:00
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <pkgecjl4a7b1lcu6c3v2e0o8tb7lk3mt9o@4ax.com>
References : 1 2 3
User-Agent : ForteAgent/7.20.32.1218
On Thu, 22 Aug 2024 09:16:04 +0200, the following appeared
in talk.origins, posted by nospam@de-ster.demon.nl (J. J.
Lodder):

Bob Casanova <nospam@buzz.off> wrote:
>
On Sun, 18 Aug 2024 00:08:49 +0100, the following appeared
in talk.origins, posted by Ernest Major
<{$to$}@meden.demon.co.uk>:
 
A study has found that lipid membranes can be selectively permeable to
one or the other sugar or amino acid enantiomer. The study used membrane
models inspired by the membranes of modern organisms, so is not directly
relevant to abiogenesis. However it still raises the possibility that
membrane selectivity was the source of chirality in biological
molecules. One possible issue is does this effect require chiral
membrane lipids; if so it only move the question of the origin of
chirality from sugars and amino acids to lipids.
>
ISTM that this is similar to the "matter/antimatter"
imbalance; neither is inherently more "natural" than the
other, but one became more prevalent. And IIRC, the m/am
imbalance is now assumed to be a matter of chance in the
original ratio. I could; of course, be mistaken in that;
it's been years since I followed it even casually.
>
https://www.biorxiv.org/content/10.1101/2024.04.23.590732v2.full.pdf
>
It isn't. The left-handed molecules can be converted into right-handed
ones, and vica versa, by taking them apart and reassembling them.
For matter/antimatter there is no such possibility.
Disassembling doesn't help,
because you cannot turn antiquarks into quarks.
 
Biological chirality is a triviality,
the matter/antimatter imbalance is a deep problem.
Where has all that antimatter gone?
>
OK, I get that. I was only commenting on the prevalence of
one form when neither seemed to be inherently preferred. Ron
corrected me on that; that there apparently *is* a preferred
chirality, at least as to biology.

I seem to remember reading, decades ago, that at least some
of the then-current thinking on the matter/antimatter
imbalance that there was once only a small imbalance, but
that mutual annihilation removed almost all of both, leaving
the current deficit of antimatter. Is that still the case?
>
--

Bob C.

"The most exciting phrase to hear in science,
 the one that heralds new discoveries, is not
 'Eureka!' but 'That's funny...'"

- Isaac Asimov


Date Sujet#  Auteur
18 Aug 24 * origin of biological chirality?23Ernest Major
18 Aug 24 `* Re: origin of biological chirality?22Bob Casanova
18 Aug 24  +* Re: origin of biological chirality?13RonO
18 Aug 24  i+* Re: origin of biological chirality?2Bob Casanova
19 Aug 24  ii`- Re: origin of biological chirality?1RonO
19 Aug 24  i+* Re: origin of biological chirality?7Pro Plyd
19 Aug 24  ii+* Re: origin of biological chirality?3Bob Casanova
19 Aug 24  iii+- Re: origin of biological chirality?1RonO
24 Aug 24  iii`- Re: origin of biological chirality?1Pro Plyd
19 Aug 24  ii+* Re: origin of biological chirality?2Stewart Robert Hinsley
19 Aug 24  iii`- Re: origin of biological chirality?1Athel Cornish-Bowden
19 Aug 24  ii`- Re: origin of biological chirality?1RonO
19 Aug 24  i`* Re: origin of biological chirality?3Athel Cornish-Bowden
19 Aug 24  i `* Re: origin of biological chirality?2RonO
19 Aug 24  i  `- Re: origin of biological chirality?1Athel Cornish-Bowden
22 Aug 24  `* Re: origin of biological chirality?8J. J. Lodder
22 Aug 24   +- Re: origin of biological chirality?1Bob Casanova
24 Aug 24   `* Neutrality of matter; matter/anti-matter Re: origin of biological chirality?6Pro Plyd
24 Aug 24    +* Re: Neutrality of matter; matter/anti-matter Re: origin of biological chirality?4Ernest Major
24 Aug 24    i`* Re: Neutrality of matter; matter/anti-matter Re: origin of biological chirality?3Bob Casanova
24 Aug 24    i `* Re: Neutrality of matter; matter/anti-matter Re: origin of biological chirality?2Ernest Major
25 Aug 24    i  `- Re: Neutrality of matter; matter/anti-matter Re: origin of biological chirality?1Bob Casanova
26 Aug 24    `- Re: Neutrality of matter; matter/anti-matter Re: origin of biological chirality?1J. J. Lodder

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