Re: origin of biological chirality?

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