Amphiphilic components of carbonaceous meteorites: origins of membrane structure

Deamer, David W.; Harang, E.; Seleznev, S. A.

doi:10.1007/bf02388854

Cited by 15 publications

(8 citation statements)

References 4 publications

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“…This oil slick could have been produced from the photopolymerization of methane or from meteorites containing hydrocarbons similar to those found in the Murchison meteorite (22). Such oil slicks would have provided strong protection because of absorbance and scattering of UV light.…”

Section: Resultsmentioning

confidence: 99%

“…It is not clear whether there was sufficient prebiotic synthesis of surfactants. However, the action of UV light on pyrene and hexadecane readily forms surface active compounds (22). These would be very effective UV protectors because of scattering effects.…”

Section: Resultsmentioning

confidence: 99%

“…The yield of polymer varies with the details of the experiment but usually is between 5% and 60% of the input carbon. We will include polycyclic aromatic hydrocarbons (22) with these tholins for the purposes of this discussion. Prebiotic cyanide polymerizations produce a very insoluble and intractable polymer in large yield (60-90% of the input carbon) along with soluble polymers (28).…”

Section: Resultsmentioning

confidence: 99%

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Oceanic protection of prebiotic organic compounds from UV radiation

Cleaves

Miller²

1998

Proc. Natl. Acad. Sci. U.S.A.

115

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It is frequently stated that UV light would cause massive destruction of prebiotic organic compounds because of the absence of an ozone layer. The elevated UV f lux of the early sun compounds this problem. This applies to organic compounds of both terrestrial and extraterrestrial origin. Attempts to deal with this problem generally involve atmospheric absorbers. We show here that prebiotic organic polymers as well as several inorganic compounds are sufficient to protect oceanic organic molecules from UV degradation. This aqueous protection is in addition to any atmospheric UV absorbers and should be a ubiquitous planetary phenomenon serving to increase the size of planetary habitable zones.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Oceanic protection of prebiotic organic compounds from UV radiation

Cleaves

Miller²

1998

Proc. Natl. Acad. Sci. U.S.A.

115

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“…Similar molecules occur in the mixture of organic compounds present in carbonaceous meteorites and have been shown to self-assemble into membranous structures (Deamer & Pashley 1989). It is significant that amphiphilic molecules have been synthesized from simple gases under simulated geothermal conditions that commonly occur in volcanic environments (McCollom et al 1999;Rushdi & Simoneit 2001).…”

Section: Primitive Self-assembly Processesmentioning

confidence: 99%

Self-assembly processes in the prebiotic environment

Deamer

Singaram

Rajamani

et al. 2006

Phil. Trans. R. Soc. B

108

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An important question guiding research on the origin of life concerns the environmental conditions where molecular systems with the properties of life first appeared on the early Earth. An appropriate site would require liquid water, a source of organic compounds, a source of energy to drive polymerization reactions and a process by which the compounds were sufficiently concentrated to undergo physical and chemical interactions. One such site is a geothermal setting, in which organic compounds interact with mineral surfaces to promote self-assembly and polymerization reactions. Here, we report an initial study of two geothermal sites where mixtures of representative organic solutes (amino acids, nucleobases, a fatty acid and glycerol) and phosphate were mixed with hightemperature water in clay-lined pools. Most of the added organics and phosphate were removed from solution with half-times measured in minutes to a few hours. Analysis of the clay, primarily smectite and kaolin, showed that the organics were adsorbed to the mineral surfaces at the acidic pH of the pools, but could subsequently be released in basic solutions. These results help to constrain the range of possible environments for the origin of life. A site conducive to self-assembly of organic solutes would be an aqueous environment relatively low in ionic solutes, at an intermediate temperature range and neutral pH ranges, in which cyclic concentration of the solutes can occur by transient dry intervals.

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“…Formation of microsystems [11] in which various chemical reactions could proceed can easily be simulated by energizing amino acid molecules that are supposed to have been ubiquitous under the primordial condition on the Earth. Chemical activity identified with simulated microsystems, however, has not yet been significant enough to guarantee emergence and sustenance of reaction loops.…”

Section: Introductionmentioning

confidence: 99%

Contribution of temperature gradient to aggregation of thermal heterocopolymers of amino acids in aqueous milieu

Imai

Shirasawa

Honda

et al. 1992

Origins Life Evol Biosphere

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We prepared thermal heterocopolymers of amino acids, aspartic acid and proline, and solubilized them in distilled water at boiling temperature. The resulting suspension was then cooled down while controlling the cooling rate. The maximum growth of phase-separated microspheres was found to occur at a finite, nonzero cooling rate. Temperature-gradient controlled growth of these microspheres indicates that aggregation of thermal heterocopolymers of amino acids in their aqueous milieu is irreversible. In view of the fact that evolutionary process is an indication of lasting physical irreversibility, thermal heterocopolymers of amino acids were shown to have an evolutionary significance in maintaining the capacity of irreversibility lasting over at least several hours.

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Amphiphilic components of carbonaceous meteorites: origins of membrane structure

Cited by 15 publications

References 4 publications

Oceanic protection of prebiotic organic compounds from UV radiation

Oceanic protection of prebiotic organic compounds from UV radiation

Self-assembly processes in the prebiotic environment

Contribution of temperature gradient to aggregation of thermal heterocopolymers of amino acids in aqueous milieu

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