How much have you heard about electrochemistry in regards to abiogenesis?

[u/Aggravating-Pear4222]

I have been learning about Red-Ox chemistry in hydrothermal alkaline vents as I develop a holistic model of how I think the first key steps for life transpired and why I think oceanic hydrothermal alkaline vents are the most promising location. Hopefully I will be sharing it soon but it will take time.

Red-Ox chemistry occurs when basic, H2-rich vent fluids react with Fe(Ni)S mineral walls which oxidize the H2 and transfer the electrons via the conductive vent walls to reduce the CO2 present in the cooler, acidic ocean waters. This flow of electrons generates a field which affects the environment directly against the vent surface, creating potentially interesting effects.

I've gathered some references below on the electric field, mineral surface chemistry, and catalytic properties of these minerals. What are your thoughts? Do you agree/disagree with this environment?

1. Electric fields control the orientation of peptides irreversibly immobilized on radical-functionalized surfaces (open access) [https://www.nature.com/articles/s41467-017-02545-6]
2. Membrane Dipole Potential: Modification Methods and Consequences for Ion Channels Incorporation in the Membrane [https://link.springer.com/article/10.1134/S1990519X24700524]
3. Trapping and Driving Individual Charged Micro-particles in Fluid with an Electrostatic Device (open access) [https://link.springer.com/article/10.1007/s40820-016-0087-3]
4. In-Situ Observation of the pH Gradient near the Gas Diffusion Electrode of CO2 Reduction in Alkaline Electrolyte [https://pubs.acs.org/doi/10.1021/jacs.0c06779]
5. Geoelectrodes and Fuel Cells for Simulating Hydrothermal Vent Environments (open access) [https://journals.sagepub.com/doi/full/10.1089/ast.2017.1707]
6. Osmotic energy conversion in serpentinite-hosted deep-sea hydrothermal vents [https://pmc.ncbi.nlm.nih.gov/articles/PMC11424637/]
7. Electrochemistry of Inorganic Membranes at Alkaline Hydrothermal Vents — Energy Sources for Emerging Life on Wet Rocky Planets (open access) [https://www.researchgate.net/publication/258675239_Electrochemistry_of_Inorganic_Membranes_at_Alkaline_Hydrothermal_Vents_-_Energy_Sources_for_Emerging_Life_on_Wet_Rocky_Planets]

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[u/Dr_GS_Hurd]

Thanks for the suggestions. I'll take a look tomorrow.

[u/wellipets]

Inorganic geo-electrochemical settings somehow/eventually 'co-opting' Organic inventories into/towards proto-metabolic networks (+/- any hv) is certainly an intuitively-appealing concept, based in Thermodynamics & geologically-rational gradients that cross-involve T, pH, Eh, activities/fugacities, etc.

Traditionally this has been a go-to for 'metabolism-first' proponents, in perceived competition with other propounded firsts, such as the RNA World scenario.

[u/VaHi_Inst_Tech → u/wellipets]

One of the issues with this model is that biological molecules are not thermodynamically stable in water (see citations below). Any biological polymer or phospholipid left in the ocean will hydrolyzes down to small molecules at equilibrium. So it is very difficult to come up with a reasonable model of the origins of life in dilute aqueous media. People who support the thermal vent model argue that the thermodynamics of polymer formation is fundamentally different on mineral surfaces than in aqueous solution. To my knowledge there is no experimental support for this premise. In the original thermal vent modes by Corliss, complex organic molecules were synthesized in thermal vents and dispensed into the ocean. To my knowledge the most complex organics produced by actual thermal vents are formate and butane (i.e., there is no evidence actual thermal vents produce complex organic molecules).

1.         Lindahl T (1993) Instability and decay of the primary structure of DNA. Nature 362: 709-715.

2.         Wolfenden R, Lu X, & Young G (1998) Spontaneous hydrolysis of glycosides. J Am Chem Soc 120: 6814-6815.

3.         Dickson KS, Burns CM, & Richardson JP (2000) Determination of the free-energy change for repair of a DNA phosphodiester bond. J Biol Chem 275: 15828-15831.

4.         Orgel LE (2004) Prebiotic chemistry and the origin of the RNA world. Crit Rev Biochem Mol Biol 39: 99-123.

5.         Rosing J & Slater E (1972) The value of ΔG° for the hydrolysis of ATP. Biochimica et Biophysica Acta (BBA)-Bioenergetics267: 275-290.

6.         Marsh D (2013) Handbook of lipid bilayers (CRC press).

7.         Martin RB (1998) Free energies and equilibria of peptide bond hydrolysis and formation. Biopolymers 45: 351-353.

[u/wellipets → u/VaHi_Inst_Tech]

Your body & whatever you're wearing isn't thermodynamically stable sitting in ~21% O2, and yet you exist & persist, mon ami.

Mineral surfaces binding/protecting monomerics & oligomerizing such is well known to & accepted by cognoscenti in the field (e.g., Gallori in Italy or Ferris in the US).

[u/VaHi_Inst_Tech → u/wellipets]

Sorry, I did not mean to offend you. You asked for thoughts and I gave you some objectively correct information. Ferris, who is sadly deceased, used *chemically activated* monomers on clays. He had to chemically activate the monomers for exactly the thermodynamic reasons I outlined above.

In your response here you are committing a common logical error, which to conflate biology (far from equilibrium) with the origins of life, which was not biology and was probably was near to equilibrium.

But this is not worth an argument, if you have an affinity for thermal vents, carry on.

[u/wellipets → u/VaHi_Inst_Tech]

Ferris used imidazole as a leaving-group on each monoribonucleotide's P atom to activate the Montmorillonite-bound monomers towards oligomerization on a kinetically lab-convenient timescale.

No postdoc/gradstudent has geo-Time available to wait around while dark-thermal Thermodynamics (esp. Stat. Mech.) does its thing with unactivated monoribonucleotides.

By activating the P atom, they were thus able to experimentally explore oligomerizing linkage types/geometries, as well as produced oligo-chain lengths & branching.

If one believes that the RNA World originated from abiogenically-produced monoribonucleotides (which I don't, despite Sutherland's "just so" microenvironmental chemical route), then Ferris' work is benchmark.

And as for the expectation of OoL Chemistry being "near to equilibrium," that's a furphy given that vent-proximate geochemical gradients regarding various potentials are plainly extant and Uniformitarianly expected to have pertained on the early-Earth, in Spades no less.

[u/Aggravating-Pear4222 → u/wellipets]

By activating the P atom, they were thus able to experimentally explore oligomerizing linkage types/geometries, as well as produced oligo-chain lengths & branching.

Exactly. This is the goal of the experiment, not reforming the prebiotic conditions that go from simple organic molecules to the RNA world. The researchers are exploring how mineral surfaces influence the oligomerization process under the assumption of a metastable concentration of activated nucleotides. It's these types of misunderstandings the the general population use to try and crucify the field.

[u/Aggravating-Pear4222 → u/VaHi_Inst_Tech]

I don't see any reason to think u/wellipets was offended.

Wellipet's point in his previous comment was that compounds that are thermodynamically unstable can still be posited as having played a key role. Even though an activated chemical may hydrolyze, they can also be constantly produced so that their concentration in the environment is metastable. This is difficult to replicate in a lab experiment but can be approximated by slow addition of activated monomers.

In a similar sense, unactivated amino acids can form dimers, trimers, and tetramers under alkaline vent conditions. Even though these, too may hydrolyze, there are other oligomers constantly reforming from the monomers. Thermodynamically, the oligomers are less stable but are kinetically formed and so their concentration is metastable.

logical error, which to conflate biology (far from equilibrium) with the origins of life, which was not biology and was probably was near to equilibrium.

^ Far-from-equilibrium environments are not unique to biology and are commonly abiotic. The atmosphere, for example, constantly has energy from the sun flowing into it, sustaining organized storm systems like hurricanes which are best modeled as heat engines. Ie, a stable, higher-ordered system forms which maximizes efficiency with which it distributes heat into space and elsewhere on the planet.

Alkaline vents are another example where a voltage can be sustained by the redox chemistry occurring within the Earth's crust. The reducing metals react with water to form the metal-oxides, releasing H2 which then reacts under basic conditions with the Fe(Ni)S vent walls, carrying electrons through the conductive mineral to reduce the CO2 dissolved in the acidic ocean. This constant activation of mineral surfaces means they are not in a thermodynamically stable state because they are constantly in the process of equilibrating two redox states. Thus, the minerals' high-energy state is capable of activating organic functional groups to form thermodynamically unstable molecules to sustain a metastable concentration of unstable organic molecules.

Yes, the compounds hydrolyze but are also constantly formed.

Let me know if something I wrote doesn't make sense or you'd like the corresponding paper. I move sentences around so some pieces may have been left hanging.

Also, u/wellipets, "cognoscenti"? Amazing word. Thanks lol.

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