Data di Pubblicazione:
2007
Citazione:
Entropy consumption in primary photosynthesis / C. Robert, R.C. Jennings, E. Belgio, A.P. Casazza, F.M. Garlaschi, G. Zucchelli. - In: BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS. - ISSN 0005-2728. - 1767:10(2007), pp. 1194-1197.
Abstract:
Knox and Parson have objected to our previous conclusion on possible negative entropy production during primary photochemistry, i.e., from
photon absorption to primary charge separation, by considering a pigment system in which primary photochemistry is not specifically considered.
This approach does not address our proposal. They suggest that when a pigment absorbs light and passes to an excited state, its entropy increases
by hν/T. This point is discussed in two ways: (i) from considerations based on the energy gap law for excited state relaxation; (ii) using classical
thermodynamics, in which free energy is introduced into the pigment (antenna) system by photon absorption. Both approaches lead us to conclude
that the excited state and the ground state are isoentropic, in disagreement with Knox and Parson. A discussion on total entropy changes
specifically during the charge separation process itself indicates that this process may be almost isoentropic and thus our conclusions on possible
negentropy production associated with the sequence of reactions which go from light absorption to the first primary charge separation event, due
to its very high thermodynamic efficiency, remain unchanged.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Energy gap law; Entropy consumption; Negentropy; Photon absorption; Photosystem; Primary photochemistry
Elenco autori:
C. Robert, R.C. Jennings, E. Belgio, A.P. Casazza, F.M. Garlaschi, G. Zucchelli
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