Prebiotic Chemistry
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Interação de aminoácidos e bases de ácidos nucléicos com minerais : um estudo de química prebiótica
Nessa tese foi realizado um estudo de Química Prebiótica, na qual o objetivo é entender como surgiu à vida na Terra. O estudo foi conduzido a partir da hipótese de Bernal, de que, minerais podem ter desempenhado um papel de proteção contra degradação por hidrolise ou radiação ultravioleta, das moléculas orgânicas ou mesmo como catalisadores na f
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/08/2012
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2. Interação de forsterita-91 e da cisteína em condições de química prebiótica utilizando diferentes técnicas espectroscópicas, químicas e mineralógicas
This work simulated prebiotic conditions existed on primordial Earth and studiedthe interaction between forsterite-91, cysteine and artificial seawater. These interactions were studied in aqueous medium at two values of pH 2.0 and 8.0. The samples of olivine plus distilled water and artificial seawater were mixed for 24h, centrifuged, the solids and supernat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/02/2012
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3. Da geração espontânea à química prebiótica
In the present paper, a historical view from spontaneous generation of life to Oparin-Haldane hypothesis was discussed. It was also showed what is the main concern of the field of prebiotic chemistry. Several aspects of prebiotic chemistry such as synthesis of biomolecules and biopolymers, primitive metabolism and genetic code, and the importance of the adso
Química Nova. Publicado em: 2003-03
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4. Surface charges and interfaces: implications for mineral roles in prebiotic chemistry
There exists an extensive literature on the possible roles of minerals in the prebiotic stages of the chemical evolution of life (Bernal 1951, Cairns-Smith 1982, Wächtershäuser 1992, Vieyra et al. 1995, Tessis et al. 1999, see Lahav (1994) for a review). Among the original proposals, minerals have been considered in: (a) processes that would discriminate m
Anais da Academia Brasileira de Ciências. Publicado em: 2000-09
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5. The Role of Biomacromolecular Crowding, Ionic Strength, and Physicochemical Gradients in the Complexities of Life's Emergence
Summary: We have developed a general scenario of prebiotic physicochemical evolution during the Earth's Hadean eon and reviewed the relevant literature. We suggest that prebiotic chemical evolution started in microspaces with membranous walls, where external temperature and osmotic gradients were coupled to free-energy gradients of potential chemical reactio
American Society for Microbiology (ASM).
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6. Identification of diamino acids in the Murchison meteorite
Amino acids identified in the Murchison chondritic meteorite by molecular and isotopic analysis are thought to have been delivered to the early Earth by asteroids, comets, and interplanetary dust particles where they may have triggered the appearance of life by assisting in the synthesis of proteins via prebiotic polycondensation reactions [Oró, J. (1961) N
National Academy of Sciences.
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7. Differential adsorption of nucleic acid bases: Relevance to the origin of life
The adsorption of organic molecules onto the surfaces of inorganic solids has long been considered a process relevant to the origin of life. We have determined the equilibrium adsorption isotherms for the nucleic acid purine and pyrimidine bases dissolved in water on the surface of crystalline graphite. The markedly different adsorption behavior of the
The National Academy of Sciences.
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8. Proof for a nonproteinaceous calcium-selective channel in Escherichia coli by total synthesis from (R)-3-hydroxybutanoic acid and inorganic polyphosphate
Traditionally, the structure and properties of natural products have been determined by total synthesis and comparison with authentic samples. We have now applied this procedure to the first nonproteinaceous ion channel, isolated from bacterial plasma membranes, and consisting of a complex of poly(3-hydroxybutyrate) and calcium polyphosphate. To this end, we
The National Academy of Sciences of the USA.
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9. Photochemical selectivity in guanine–cytosine base-pair structures
Prebiotic chemistry presumably took place before formation of an oxygen-rich atmosphere and thus under conditions of intense short wavelength UV irradiation. Therefore, the UV photochemical stability of the molecular building blocks of life may have been an important selective factor in determining the eventual chemical makeup of critical biomolecules. To in
National Academy of Sciences.