Book contents
- Frontmatter
- Contents
- Contributors
- THE MOLECULAR ORIGINS OF LIFE CAMBRIDGE
- Introduction
- Part I Setting the stage
- Part II Organic molecules on the early Earth
- Part III Possible starts for primitive life
- 8 Membrane compartments in prebiotic evolution
- 9 Origin of life in an iron–sulfur world
- 10 Clues from present-day biology: the thioester world
- 11 Origins of the RNA world
- 12 Catalyzed RNA synthesis for the RNA world
- 13 Catalysis in the RNA world
- 14 Self-replication and autocatalysis
- Part IV Clues from the bacterial world
- Part V Clues from other planets
- Conclusion
- Index
14 - Self-replication and autocatalysis
Published online by Cambridge University Press: 06 January 2010
- Frontmatter
- Contents
- Contributors
- THE MOLECULAR ORIGINS OF LIFE CAMBRIDGE
- Introduction
- Part I Setting the stage
- Part II Organic molecules on the early Earth
- Part III Possible starts for primitive life
- 8 Membrane compartments in prebiotic evolution
- 9 Origin of life in an iron–sulfur world
- 10 Clues from present-day biology: the thioester world
- 11 Origins of the RNA world
- 12 Catalyzed RNA synthesis for the RNA world
- 13 Catalysis in the RNA world
- 14 Self-replication and autocatalysis
- Part IV Clues from the bacterial world
- Part V Clues from other planets
- Conclusion
- Index
Summary
Introduction
Long before science began, the question of the origin of life was answered by religion and mythology. With the work of Lamarck and Darwin, science started to try to give new answers to an old question. The theory of Darwinian evolution describes the origin of biological information. In general, an evolving system (i.e., an information-gaining system) is able to metabolize, to self-replicate, and to undergo mutations (as was stated by Oparin in 1924). Thus self-replication is one of the three criteria that enable us to distinguish nonliving from living systems. Since nucleic acids carry the inherent ability for complementary base-pairing (and replication), they are very likely candidates to have been the first reproducing molecules. Kuhn and others (Crick 1968; Orgel 1968; Eigen and Schuster 1979; Kuhn and Waser 1981; for a review, see Joyce 1989) have drawn the picture of an RNA world that might have existed before translation was invented. This picture was supported by the finding that RNA (and also DNA) can act as an enzymelike catalyst (Sharp 1985; Cech 1987; Joyce 1989; Breaker and Joyce 1994). It is a challenge for organic and bioorganic chemists to trace back the original path of evolution by “reinventing” simple self-replicating systems in the lab and to learn more about the principles of replication on a molecular scale.
A simple three-step model can be used to conceptualize the process of molecular self-replication (Figure 14.1). In this model, the template molecule T is self-complementary and thus able to autocatalytically augment itself. In the first step, the template T reversibly binds its constituents A and B to yield a termolecular complex M.
- Type
- Chapter
- Information
- The Molecular Origins of LifeAssembling Pieces of the Puzzle, pp. 295 - 312Publisher: Cambridge University PressPrint publication year: 1998
- 7
- Cited by