The Prevailing Catalytic Role of Meteorites in Formamide Prebiotic Processes
نویسندگان
چکیده
Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i) as providers of impact energy during their passage through the atmosphere; (ii) as agents of geodynamics, intended both as starters of the Earth's tectonics and as activators of local hydrothermal systems upon their fall; (iii) as sources of organic materials, at varying levels of limited complexity; and (iv) as catalysts. The consensus about the relevance of these functions differs. We focus on the catalytic activities of the various types of meteorites in reactions relevant for prebiotic chemistry. Formamide was selected as the chemical precursor and various sources of energy were analyzed. The results show that all the meteorites and all the different energy sources tested actively afford complex mixtures of biologically-relevant compounds, indicating the robustness of the formamide-based prebiotic chemistry involved. Although in some cases the yields of products are quite small, the diversity of the detected compounds of biochemical significance underlines the prebiotic importance of meteorite-catalyzed condensation of formamide.
منابع مشابه
The key role of meteorites in the formation of relevant prebiotic molecules in a formamide/water environment
We show that carbonaceous chondrite meteorites actively and selectively catalyze the formation of relevant prebiotic molecules from formamide in aqueous media. Specific catalytic behaviours are observed, depending on the origin and composition of the chondrites and on the type of water present in the system (activity: thermal > seawater > pure). We report the one-pot synthesis of all the natura...
متن کاملMeteorites as catalysts for prebiotic chemistry.
Meteorite late heavy bombardment was a major event after the accretion of the earth. The relevance of organic syntheses driven by impact shocks was first proposed by Chyba and Sagan in 1992, based on the scanty indications available at the time. How would the contribution by meteorites to an early earth organic pool compare with the syntheses these meteorites might have induced after their impa...
متن کاملMeteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation.
Liquid formamide has been irradiated by high-energy proton beams in the presence of powdered meteorites, and the products of the catalyzed resulting syntheses were analyzed by mass spectrometry. Relative to the controls (no radiation, or no formamide, or no catalyst), an extremely rich, variegate, and prebiotically relevant panel of compounds was observed. The meteorites tested were representat...
متن کاملThe peptide-catalyzed stereospecific synthesis of tetroses: a possible model for prebiotic molecular evolution.
Using a water-based prebiotic model of sugar synthesis involving glycolaldehyde self-condensation, we demonstrate that homochiral L-dipeptide catalysts lead to the stereospecific syntheses of tetroses. The asymmetric effect is largest for erythrose, which may reach a D-enantiomeric excess of >80% with L-Val-L-Val catalyst. Based on results obtained with various peptides, we propose a possible c...
متن کاملHeuristic Approach to Understanding the Accumulation Process in Hydrothermal Pores
One of the central questions of humankind is: which chemical and physical conditions are necessary to make life possible? In this “origin-of-life” context, formamide plays an important role, because it has been demonstrated that prebiotic molecules can be synthesized from concentrated formamide solutions. Recently, it could be shown, using finite-element calculations combining thermophoresis an...
متن کامل