Re: Vent Life? Not the O2 dependent part


"Perplexed in Peoria" <jimmenegay@xxxxxxxxxxxxx> wrote in
message news:dlh6sh$24i$1@xxxxxxxxxxxxxxxxxxxxxx
>
> "Anthony Cerrato" <tcerrato@xxxxxxxxxxxxx> wrote in
message news:dlft91$2ft8$1@xxxxxxxxxxxxxxxxxxxxxx
> >
> > "Catherine Woodgold" <an588@xxxxxxxxxxxxxxxxxxx> wrote
in
> > message news:dldgff$1e08$1@xxxxxxxxxxxxxxxxxxxxxx
> > > (TomHendricks474@xxxxxx) writes:
> > > > I'm a sunlight chauvinist too.
> > > > Those who favor the vent origin scenario must do so
> > > > without the O2 dependency.
>
> And, of course, they DO do so without an O2 dependency.
Even
> modern vent systems have an autotrophic base trophic level
which
> is O2 independent. The O2 dependent tubeworms and such
are
> parasites and predators on the real primary producers.
And,
> unlike life at the surface, the primary producers in vent
> systems don't even produce O2 as a byproduct.
>
> > > Well, there are some organisms that don't use
> > > O2, aren't there? What about anaerobic bacteria?
> >
> > We don't need no stinkin' O2 for intelligent life on
other
> > planets. Sulfur might do just fine on planets with
extremes
> > of temperature. For that matter, we don't need no
stinkin'
> > DNA or RNA for life either--anyone ever think of
> > metal-polyamine complexes bonded to various other
central
> > substrates as coding information carriers?
>
> Uh, yes. Someone has thought of that. I have. Or at
least the
> metals and the polyamines. Though I am not sure what you
mean
> by a 'central substrate'. In my model, the metal ions are
> central.


Yes, that would be just fine. The only reason I stuck
"central substrate" in was to maximize the possible
diversity of variants with differing geometries...almost
anything that acts as a polymer-like support would do (or as
you note, none at all,) 'course there are stringent spatial
and bond stability restrictions that would obtain on
geometry, H-bonding, etc. My favorite example fitting your
model is a polyalkyl tetramine-metal complex, e.g., chain of
>=4 methylene groups with 2 aminos stuck on both ends--this
chain is long enough to complex, actually chelate, many
metals; it chelates metals such as Cu+
/Cu++, and Cr+++ at room temp. The Cr+++ complex, Reinecke
salt, NH4[Cr(NH3)2(SCN)4]·H2O, is a good example--it has
hexagonal symmetry of the ligands. The anhydrous salt is
soluble in certain alkylamine solvents and amine/aromatic
hydrocarbon mixtures, e.g.10% aqueous butylamine in benzene.
(The latter is a lovely, intense red solution which can be
extracted from Aq. solns. of the salt.)

> > Such forms of
> > life might well exist on gas giants at high pressure and
low
> > temperatures. ...tonyC
>
> But that is a possibility I hadn't considered. ISTM that
to have
> soluble metal ions, you need a solvent of water or
ammonia, or
> both. I am not aware of any gas giant models that suggest
an
> aquaeous layer in the structure.

Well, as noted above, some chelates are soluble in low or
moderate amine concentration solutions and can be extracted
from water. Water may not be necessary at all for metal
dissolution in certain other organic solvent mixtures. There
may be liquid (not water) layers in some gas giants, but
there are many possible planets and their satellites that
may have polar liquids on the surface--ammonia would be
fairly polar and hydrogen bonding, though much less so than
water.

Also, there has been much speculation about the possibility
of life originating in the high pressure atmospheres of gas
giants themselves, e.g., "gasbag life." Very simple life
might start there.
Sure it's unlikely, but... In any event, I was thinking less
of the giant planets and more of much smaller ones--rather
than only imagining life-as-we-know-it, why should life be
restricted to that on these planets just 'cause that's what
we have on Earth? ...tonyC


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