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Basic organization of life| old_uid | 11383 |
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| title | Basic organization of life |
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| start_date | 2012/05/15 |
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| schedule | 17h |
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| online | no |
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| location_info | 1er étage, salle 28 132 |
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| summary | The quest for minimal life has been a long one. Tibor Gánti, a chemical engineer by training, first presented his ideas in the form of a book in Hungarian in 1971 in a popular science book disguise, an updated version of which was published (with valuable other material and comments included) by Oxford University Press in 2003 {1}. Gánti realized that the problem of life in general cannot be scientifically studied without a phenomenological and a more mechanistic level. At the phenomenological level, he has given a list of life criteria that should apply to any system that is usefully regarded as living. In contrast, a model of living systems that includes a description of chemical mechanisms must be tied to a certain level of the organizational hierarchy: cells and multicellular living systems cannot be given the same description; one reason being that the latter consist of components that are also alive (the cells). The chemoton model describes a spatially reproducing chemical supersystem consisting of three different autocatalytic systems: metabolism, template replication and membrane growth. This work is one of the main intellectual sources of the now emerging field of systems chemistry, which deals with the analysis and synthesis of coupled autocatalytic chemical systems {2,3}. Its main insight was recapitulated decades later in several forms (e.g. {4}). Nobody knows how the chemoton with all its three subsystems could be running without enzymatic aid, but it is an ultimate goal of systems chemistry to achieve this. Needless to say, such systems could have been of paramount importance for the origin of life. Right now systems chemistry is setting more modest goals, such as the synthesis of certain system doublets (out of metabolism, template replication and membrane growth one can compose three doublets), which could be regarded as infrabiological systems {3,5,6}). Remarkably, two of them have been anticipated in Gánti’s original work, along with a metabolically complex RNA world. The idea has grown into a full-blown theory at the interface of theoretical biology and chemistry {7,8}.
Références :
{1} Gánti T "The Principles of Life." Oxford University Press; 2003.
{2} Hayden et al. Angew Chem Int Ed Engl 2008, 47:8424-8 [PMID:18780409].
{3} Griesemer and Szathmáry: "Gánti's chemoton model and life criteria." In: Protocells. Bridging Nonliving and Living Matter. S Rasmussen et al. (Eds). The MIT Press Cambridge, Ma, London, England; 2009, pp481-512.
{4} Rasmussen et al. Science 2004, 303:963-5 [PMID:14963315].
{5} Szostak et al. Nature 2001, 409:387-90 [PMID:11201752].
{6} Mansy et al. Nature 2008, 454:122-5 [PMID:18528332].
{7} Ganti T: "Chemoton Theory Vol. 1. Theoretical Foundations of Fluid Machineries." Kluwer Academic/Plenum Publishers; 2003.
{8} Ganti T: "Chemoton Theory Vol. 2. Theory of Living Systems." Kluwer Academic/Plenum Publishers; 2003. |
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| responsibles | Longo, Mossio, Barandiaran |
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