Oxygenic Photosynthesis but working with less energy input
Lundi 30 septembre 2019 11:00
- Duree : 1 heure
Lieu : IRIG, Bât 10-05 - room 445, CEA Grenoble, 17 rue des martyrs
Orateur : Alfred William RUTHERFORD (Chair of Biochemistry of Solar Energy, Department of Life Sciences, Imperial College London)
hlorophyll-a photochemistry using red light (680-700 nm) is near-universal and is sometimes considered to define the energy limit for oxygenic photosynthesis, the so-called red limit. We recently reported [1] the isolation and biophysical study of photosystems from a cyanobacterium grown in far-red light (750 nm). The few long-wavelength chlorophyll-f molecules and the single chlorophyll-d present are well resolved from each other and from the majority pigment, chlorophyll-a. Charge separation in Photosystem I and II uses chlorophyll-f at 745 nm and chlorophyll-f (or -d) at 727 nm, respectively. Each photosystem also has a few even longer-wavelength chlorophylls-f that collect light and pass excitation energy up-hill to the photochemically active pigments. Thus by using a only few far-red pigments ( 8 in PS1, 5 in PS2) in specific locations, these photosystems can do oxygenic photosynthesis but nominally using 110 meV less energy for the primary charge separation. These studies provide several new insights including : i) the nature of charge separation and excitation transfer in the standard chlorophyll-a-containing photosystems, ii) a new slant on photosystem evolution ; and iii) the energy limits on oxygenic photosynthesis [1].
[1] Nürnberg D.J., Morton J., Santabarbara S., Telfer A., Joliot P., Antonaru L.A., Ruban A.V., Cardona T., Krausz E., Boussac A., Fantuzzi A, Rutherford A.W. (2018) Science 360, 1210- 1213 Photochemistry beyond the red limit in chlorophyll f–containing photosystems
Contact : odile.rossignol@cea.fr
Discipline évènement : (Biologie / Chimie)
Entité organisatrice : (CEA / IRIG)
Nature évènement : (Séminaire)
Evènement répétitif : (Séminaire PCV)
Site de l'évènement : Site CEA avec accès badge
Prévenir un ami par email
Télécharger dans mon agenda