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A tárgy természete...

A tárgy természete. A biológiai tudományok egysége Molekuláris, organizmikus és populációs megközelítés Érdekes de NEHÉZ Aki nem akar figyelni, az menjen ki! Vizsga: írásban. Utóvizsga: szóban Vizsganyag: az előadások (órai jegyzet és diasorozat, cikkgyűjtenény).

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A tárgy természete...

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  1. A tárgy természete... • A biológiai tudományok egysége • Molekuláris, organizmikus és populációs megközelítés • Érdekes de NEHÉZ • Aki nem akar figyelni, az menjen ki! • Vizsga: írásban. Utóvizsga: szóban • Vizsganyag: az előadások (órai jegyzet és diasorozat, cikkgyűjtenény)

  2. Az élet kettős természete Eörs Szathmáry Collegium Budapest Eötvös University

  3. Miért kettős? • Homeosztázis—disszipatív—anyagcsere • Egyirányú vezérlés és öröklődés • A láng és az öröklődő tulajdonságokkal rendelkező sejt különbözősége

  4. Great thinkers on the nature of life Erwin Schrödinger Gottfried Leibniz John Maynard Smith Freeman Dyson

  5. Leibniz • Az „isteni gépek végtelenül oszthatónak tűnnek • A gépszerű működés a „molekuláris” dimenzióban is érvényesül

  6. Schrödinger • A gén mint aperiodikus kristály • Az entrópia alacsony szintjének fenntartása állandó munkavégzést igényel

  7. Maynard Smith • Anyagcsere és homeosztázis • Genetikai szabályozás • Az evolvabilitást az utóbbi adja

  8. Freeman Dyson • Az élet kettős eredete • Először az anyagcsere és a homeosztázis, nukleinsvak nélkül • A gének mint a rendszer parazitái jelenhettek meg

  9. An irreversible system • A  B

  10. A reversible reaction • A  B • Le Chatelier-Braun principle

  11. A reversible, closed reaction system

  12. Reaction systems • An open, almost reversible system • A closed, reversible cycle

  13. Closed and open systems Alul: a stacionárius állapot (steady state)

  14. The skeleton of sugar decomposition

  15. Chemical cycles are metabolicengines • The cycle as a whole is a catalyst • The Noble prize of Szent-Györgyi was awarded for catalysis by fumaric acid • Krebs has recognized the whole cycle • Enzymes are superimposed on the metabolic cycle

  16. A simple chemical cycle • It is formally a unit composed of a closed and an open part • Acts as a catalys

  17. Engines operate in cycles, and are hence are dynamically stable

  18. Tibor Gánti • Born in 1933 • Chemical engineer • Patents in industrial biochemistry (artificial metabolism) • Syntheses using the controlled operation of enzymatic reaction networks • First book on molecular biology in Hungary (1966)

  19. The first edition of the Principles • A serious book in a popular science disguise (1971) • There was no other way to publish • Proposal included the term “chemoton” • ‘reductionist’ and ‘vitalist’ at the same time!

  20. The investigation of life criteria: absolute criteria • Inherent unity • Metabolism • Inherent stability • Information carrying subsystem • Processes regulated and controlled by a programme VERBAL AND PHENOMENOLOGICAL

  21. Quest for a biological minimal system • Chemical supersystem • Should be conceptually as simple as possible • Must not necessarily be realizable in its simplest form • Comparison with other elementary units (such as the elementary cell in crystallography) • FORMAL AND EXACT

  22. The latest edition: OUP 2003 • After several editions in Hungarian • Two previous books (the Principles and Contra Crick) plus one essay • Essays appreciating the biological and philosophical importance

  23. Enzymes and cycle stoichiometry Very important: the cyclic process sign with the number of turns

  24. Structures built of amphipathic molecules A two-dimensional fluid

  25. A self-reproducing vesicle (1978) • Metabolism and reproduction • No genetic subsystem

  26. Pathways of supersystem evolution metabolism MB boundary MT MBT template BT INFRABIOLOGICAL SYSTEMS

  27. Organisation of chemical systems into a supersystem (1974) • CHEMOTON: a particular supersystem which is also a biological minimal system

  28. Gánti’s chemoton model metabolism template copying membrane growth ALL THREE SUBSYSTEMS ARE AUTOCATALYTIC

  29. The assembly of RNA structures • Combinatorial assembly of RNA structures • Submitted to selection for function between chemotons • 1979

  30. The channelled assembly of ribozymes (1983) • The presence of substrates gives guidance to ribozyme assembly • Good enzymes and bad enzymes will affect the fitness of the chemotons

  31. Venter: professional but trivial (synthetic biology)

  32. The monograph (Kluwer 2003)

  33. The chemoton symbol

  34. Evolution towards a Borromean arrangement? Chemoton symbol Borromean rings

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