A possible energetic role of mineral surfaces in chemical evolution

Bio-soliton model that predicts non-thermal electromagnetic frequency bands, that either stabilize or destabilize living cells

Solitons, as self-reinforcing solitary waves, interact with complex biological phenomena such as cellular self-organization. A soliton model is able to describe a spectrum of electromagnetism modalities that can be applied to understand the physical principles of biological effects in living cells, as caused by endogenous and exogenous electromagnetic fields and is compatible with quantum coherence. A bio-soliton model is proposed, that enables to predict which eigen-frequencies of non-thermal electromagnetic waves are life-sustaining and which are, in contrast, detrimental for living cells. The particular effects are exerted by a range of electromagnetic wave eigen-frequencies of one-tenth of a Hertz till Peta Hertz that show a pattern of 12 bands, and can be positioned on an acoustic reference frequency scale. The model was substantiated by a meta-analysis of 240 published articles of biological electromagnetic experiments, in which a spectrum of non-thermal electromagnetic waves were exposed to living cells and intact organisms. These data support the concept of coherent quantized electromagnetic states in living organisms and the theories of Fröhlich, Davydov and Pang. It is envisioned that a rational control of shape by soliton-waves and related to a morphogenetic field and parametric resonance provides positional information and cues to regulate organism-wide systems properties like anatomy, control of reproduction and repair.

Did life begin on the beach?

Water is one of the prerequisites of life. Further requirements are the existence of a system of interacting organic molecules capable of capturing and converting the supply of external energy and elaborating the replicating function that is needed for propagation. None of this would be possible without the existence of some means of concentrating, selecting, and then containing these mutually interacting substances in proximity to one another, i.e., a primitive cell. Starting from this hypothesis we propose a model for the development of life on Earth. Our model embodies the following new features: (1) rapid cycles of catalysis and transport of material, (2) desegregation (separation by tidal action and degradation by catalysis) as well as segregation (by chromatography on tidal beaches), (3) cross-catalysis instead of auto-catalysis, as well as (4) compartmentalization, although the latter idea is of course not new. But our "lipid first" model, in contrast to earlier "peptide first" or "RNA first" models, provides for the compartments needed to act as a cradle for the subsequent development of information- rich molecules like peptides and RNA. If anything, the earliest information-rich molecules were probably membrane-spanning peptides/proteins.

The influence of prebiotic-type organic molecules on the crystallization of Al and Mg hydroxides

It is now well accepted that clays could have concentrated prebiotic organic molecules, protected them from UV radiation and served as templates and catalysts in their prebiotic evolution. A complementary question is: How did prebiotic organics in the oceans, in ground water, or in hydrothermal solutions affect the formation and inorganic evolution of oxides, hydroxides, and clay minerals? In this study predominantly amorphous Al oxyhydroxides (Al gels) and crystalline Mg hydroxyoxides were synthesized, and then crystallized and recrystallized respectively, to Al and Mg hydroxides via wet and dry (w/d) cycling using both water and organic solutions. The products that resulted were examined using IR spectroscopy and X-ray diffraction (XRD). XRD scans of the products formed by w/d cycling of the Al gels with either water or 0.1 M aqueous solutions of methanol or formaldehyde showed that bayerite (alpha Al2O3) was the major phase formed. The acetonitrile treated sample exhibited the most defined XRD peaks, and no crystalline phase could be observed by XRD of the 0.1 M formamide solution treated sample. Cycling the Mg hydroxyoxide with water, or 0.1 M solutions of methanol, formamide, formaldehyde, or acetonitrile resulted in the formation of brucite (Mg(OH)2) (in varying amounts) and of three unidentified phases. One unidentified phase, 'phase II', was observed in the formaldehyde cycled sample (and tentatively identified in the methanol and formamide cycled samples), 'phase III' in the formamide and formaldehyde cycled sample, and 'phase IV' in only the formaldehyde. XRD peaks with a spacing of approximately 11.5 Angstrom (assigned to phase III) suggest intercalation of formamide and formaldehyde into the interlayer spaces of the brucite. Phosphate treatment, prior to w/d cycling with water, and also with the above mentioned organics, while totally preventing subsequent formation of any crystalline Al hydroxide, enhanced the formation of Mg phases, shown by XRD data. Formation of brucite was impeded only by w/d cycling using concentrated methanol solution, but even these effects were reversible. The XRD scans of the products resulting from the aqueous and organic solution cycling treatments of the Mg starting materials showed peaks due to brucite and three unidentified phases. Only the brucite is evident in oriented sample XRD scans of the Mg starting material when treated with methanol, formamide, and acetonitrile. In random powder sample XRD scans of the Mg starting material treated with: 1) methanol--the unidentified phase 11 is evident, 2) formamide--phase II and III are seen, and 3) formaldehyde--phases II, III, and IV are evident.

Biochemical evolution. I. Polymerization On internal, organophilic silica surfaces of dealuminated zeolites and feldspars

Catalysis at mineral surfaces might generate replicating biopolymers from simple chemicals supplied by meteorites, volcanic gases, and photochemical gas reactions. Many ideas are implausible in detail because the proposed mineral surfaces strongly prefer water and other ionic species to organic ones. The molecular sieve silicalite (Union Carbide; = Al-free Mobil ZSM-5 zeolite) has a three-dimensional, 10-ring channel system whose electrically neutral Si-O surface strongly adsorbs organic species over water. Three -O-Si tetrahedral bonds lie in the surface, and the fourth Si-O points inwards. In contrast, the outward Si-OH of simple quartz and feldspar crystals generates their ionic organophobicity. The ZSM-5-type zeolite mutinaite occurs in Antarctica with boggsite and tschernichite (Al-analog of Mobil Beta). Archean mutinaite might have become de-aluminated toward silicalite during hot/cold/wet/dry cycles. Catalytic activity of silicalite increases linearly with Al-OH substitution for Si, and Al atoms tend to avoid each other. Adjacent organophilic and catalytic Al-OH regions in nanometer channels might have scavenged organic species for catalytic assembly into specific polymers protected from prompt photochemical destruction. Polymer migration along weathered silicic surfaces of micrometer-wide channels of feldspars might have led to assembly of replicating catalytic biomolecules and perhaps primitive cellular organisms. Silica-rich volcanic glasses should have been abundant on the early Earth, ready for crystallization into zeolites and feldspars, as in present continental basins. Abundant chert from weakly metamorphosed Archaean rocks might retain microscopic clues to the proposed mineral adsorbent/catalysts. Other framework silicas are possible, including ones with laevo/dextro one-dimensional channels. Organic molecules, transition-metal ions, and P occur inside modern feldspars.

A review of conditions affecting the radiolysis due to 40K on nucleic acid bases and their derivatives adsorbed on clay minerals: implications in prebiotic chemistry

This paper describes the possible effects of ionizing radiation arising from long-lived soluble radionuclides within clays, in particular 40K, at the epoch of the emergence of life on Earth. The free dispersion of soluble radionuclides constitutes an effective in situ irradiation mechanism that might have acted upon adsorbed nucleic bases and their derivatives on clays, inducing chemical changes on these organic molecules. Several types of well documented reactions for radiolysis of nucleic acid bases and their derivatives are known, even at low doses (i.e., 0.1 Gy). For example, estimates with a dose rate calculated from 40K from deep sea clays at 3.8 Ga ago, indicates that over a period of 1000 years the amount of organic material transformated is 1.8 X 10(-7) moles/kg-clay. Although ionizing radiation may also induce synthetic reactions with prebiological interest, all in all these considerations indicate that nucleic acid bases and their derivatives adsorbed on clays were exposed for long periods to degradation conditions. Such situation promotes decomposition of organic molecules rather than protection of them and enhancement of farther polymerization, as it has been usually taken for granted.

Luminescence and ESR studies of relationships between O(-)-centres and structural iron in natural and synthetically hydrated kaolinites

Luminescence, induced by dehydration and by wetting with hydrazine and unsymmetrically substituted hydrazine, and related ESR spectra have been observed from several kaolinites, synthetically hydrated kaolinites, and metahalloysites. The amine-wetting luminescence results suggest that intercalation, not a chemiluminescence reaction, is the luminescence trigger. Correlation between hydration-induced luminescence and g = 2 ESR signals associated with O(-)-centres in several natural halloysites, and concurrent diminution of the intensity of both these signal types as a function of aging in two 8.4 angstroms synthetically hydrated, kaolinites, confirm a previously-reported relationship between the luminescence induced by dehydration and in the presence of O(-)-centres (holes, i.e., electron vacancies) in the tetrahedral sheet. Furthermore, the ESR spectra of the 8.4 angstroms hydrate showed a concurrent change in the line shape of the g = 4 signal from a shape usually associated with structural Fe in an ordered kaolinite, to a simpler one typically observed in more disordered kaolinite, halloysite, and montmorillonite. Either structural Fe centres and the O(-)-centres interact, or both are subject to factors previously associated with degree of order. The results question the long-term stability of the 8.4 angstroms hydrate, although XRD does not indicate interlayer collapse over this period. Complex inter-relationships are shown between intercalation, stored energy, structural Fe, and the degree of hydration which may be reflected in catalytic as well as spectroscopic properties of the clays.

Chemical Reactions on Clays

Layer aluminosilicates catalyze reactions in numerous ways. They stabilize high-energy intermediates. They can store energy in their lattice structures and can release it in the form of chemical energy. They can catalyze redox reactions and can serve as photocatalytic devices. They often exhibit high surface acidity. Organic reactions that are catalyzed by the agency of days are reviewed. The role of clays in prebiotic chemistry is also examined.