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ORIGINE DEL MATERIALE GENETICO SU PARTICELLE MINERALI

ORIGINE DEL MATERIALE GENETICO SU PARTICELLE MINERALI. Enzo Gallori DBAG- Università di Firenze. Erwin Schr ö dinger. “ What is Life ”, 1944. DNA. Phosphate. Adenine (A) Guanine (G). Pu Py. Base. Thymine (T) Cytosine (C). Sugar. Nucleotide. The DNA Molecule.

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ORIGINE DEL MATERIALE GENETICO SU PARTICELLE MINERALI

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  1. ORIGINE DEL MATERIALE GENETICO SU PARTICELLE MINERALI Enzo Gallori DBAG- Università di Firenze

  2. Erwin Schrödinger • “What is Life”, 1944

  3. DNA

  4. Phosphate Adenine (A) Guanine (G) Pu Py Base Thymine (T) Cytosine (C) Sugar Nucleotide The DNA Molecule

  5. Complementary Base Pairing A = T G C A T G C “Genetic Information” T A C G DNA The Transition from Chemistry to Biology:Nucleic Acids (DNA, RNA) asStores of Biological Information

  6. Transcription Traduction Replication DNA RNA Proteine Genotype Phenotype The basic principle of biology

  7. A A T T T A T A G G C C C G G C T T A A A T T A C C G G C G C G Perpetuation of Information Replication

  8. Come si originarono i primi polimeri replicativi?

  9. Building Code • Synthesis and accumulation of precursors (i.e.nucleotides) • Joining of precursors into larger molecules (i.e.DNA, RNA) • Protection from degradation  Persistence • Expression of biological “potentiality” of the informational molecule

  10. BIG BANG Creation of the Elements Biogenic elements Organic Molecules LIFE H C O N P

  11. “The Primordial Soup” Electrodes S.L. Miller (1953) Refrigerator “Primordial” Soup Synthesis and Accumulation of Precursors: A.I. Oparin (~1920) - J.B.S. Haldane (~1930) Prebiotic Chemistry

  12. Diffuse Clouds Core H, CO, PAH Cosmic radiation Dense Clouds H CH CO PAH Ice : Comets Meteorites Early Earth Synthesis and Accumulation of Precursors: Molecules from Space Amminoacids Ethers PAH N Bases ?

  13. U.V. radiation Ice Silicate granule Hydrocarbon Water Methanol Carbon monoxide Carbon dioxide Chemistry in Cosmic Dust Laboratory simulations (L.J.Allamandola and coll., 1995-2000) Complex organics • Ketons • Aminoacids • Quinones • N Bases?

  14. Building Code • Synthesis and accumulation of precursors (i.e.nucleotides) • Joining of precursors into larger molecules (i.e.DNA, RNA) • Protection from degradation  Persistence • Expression of biological “potentiality” of the informational molecule

  15. Polimerizzazione • Ricerca classica: Chimica in soluzione acquosa In queste condizioni: è favorital’idrolisi e non la polimerizzazione. • Chimica su superficie minerale  Argille

  16. J.D. Bernal (1951) “. . . clays and other minerals were necessary to: 1) Concentrate the organics present in a dilute ocean by adsorption; 2) Protect these organics from destruction by U.V. light; 3) Catalyze the polymerization of adsorbed organics . . . ”

  17. Joining of precursors into larger molecules:Mineral surfaces • May catalyze the formation of oligonucleotides and peptides up to 50-mer long Ertem and Ferris (1996), Nature 379: 238-240 Ferris et al. (1996), Nature 381: 59-61 C A C A G T A C A G A G T

  18. DNA RNA Clay minerals: • montmorillonite (M) • kaolinite (K) Nucleic acid-clay complexes

  19. K-Chromosomal DNA (X 154,000) K-Plasmid DNA (X 271,500) Electron Microscopy (T.E.M.) Franchi et al., 1999, OLEB 29: 297-315

  20. X-Ray Analysis of M-nucleic acid complexes Franchi et al., 1999, OLEB 29: 297-315

  21. Role of cations in theadsorption of nucleic acids

  22. FT-IR Analysis Franchi et al., 1999, OLEB 29: 297-315

  23. Pyrimidine Dimers U.V. radiation K-Chromosomal DNA (X 154,000) Resistenza degli Acidi Nucleiciadsorbiti all’argilla La forrmazione dei dimeri di Timina è ridotta nel caso del DNA adsorbito all’argilla Gallori et al., (2004)

  24. Did stone nurture the first life on earth?

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