Naslov
Enzymes and living cells as functionally optimized systems for coupling thermodynamic to biological evolution

Autori
Juretić, Davor

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Entropy in Biomolecular Systems - MedILS Workshop, Split, Croatia, August 2008 / - , 2008

Skup
Entropy in Biomolecular Systems Workshop

Mjesto i datum
Split, Hrvatska, 10.08.2008. - 16.08.2008

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
entropy production; information entropy; evolution

Sažetak
A conjectured codicil to the 2nd law – known as the Maximum Entropy Production (MEP) principle – states that everything tends towards disorder as fast as possible. At present time the MEP principle is the most powerful selection principle in steady state irreversible thermodynamics relevant for the emergence of both close to equilibrium and far from equilibrium steady states in systems driven by some external force. It can be regarded as an evolutionary selection principle because it directs the evolution of driven systems toward most probable steady states. When quasi steady states can be defined in biology, such states of biological macromolecules and living cells are highly complex and therefore expected to have low entropy which seemingly contradicts the predictions of the MEP principle. Fortunately, Shannon’ s definition of information entropy, maximum information entropy (MaxEnt) principle by Jaynes, and Dewar’ s recent proof that the MEP principle is the corollary of the MaxEnt principle, come to our help to resolve this conundrum. We shall present several modelling examples from the field of bioenergetics which support the hypothesis that biologically relevant steady states of enzymes and protein complexes are indeed optimized in accord with MaxEnt and MEP principle. We postulate that functional design of complex biological networks, compatible with external non-equilibrium constraints, can be predicted by using MEP and MaxEnt physical selection principles. If additional support is found for the hypothesis that MaxEnt and MEP principles, together with appropriately modified Kirchhoff’ s laws, are relevant for the present day operation of biological networks, one can infer that same principles worked hand in hand with Darwinian evolution to produce optimized structural and functional design of biological structures. For quasi steady state of living entities (cells, living beings) this hypothesis translates into requirement that maximal possible entropy export from living cells is achieved spontaneously (compatible with given constraints) as the most probable outcome of the MaxEnt design which is also achieved spontaneously (through Darwinian evolution) for cellular functional networks. This insight, based on the MEP principle codicil to the 2nd law, leads to the evolution coupling hypothesis proposed by ourselves, namely that biological evolution accelerates the thermodynamic evolution of the environment, which may have some relevance pertaining to the fundamental question what life is and why it exists in the Universe.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Biologija

POVEZANOST RADA