Carotenoids schematic representation

Fig. 13. Schematic representation of carotenoid tripiet state Car formation in photosynthetic bacteria when forward electron transfer is biocked. See text for discussion. Figure adapted from Frank and Cogdel) (1993) The photochemistry and function of carotenoids in photosynthesis. In A Young and G Britton, (eds) Carotenoids in Photosynthesis, p 301. Chapman and Hall.

Fig. 14. Schematic representation of removal of BChl (Bb) from the carotenoldless Rb. sphaeroides reaction center by treatment with borohydride treatment and subsequent incorporation of the carotenoid into the RC to form a wiid strain-like compiex. See text for discussion,...

Fig. 2. Schematic representation of the hydrophobic core of the lipid bilayer and the carotenoid pigments oriented differently depending on their stereochemical structure. The picture refers to EYPC membrane and different pigments indicated. For details see Table I.

A schematic representation of electronic energy levels across the membrane is shown in Figure 4. The broken line across the 40 A barrier represents the lowered barrier when carotenoids are present. The solid lines in the small potential wells represent the ground and first excited states of chlorophyll. The dotted line represents a hypothetical lowering of the solution membrane energy barrier by excited phycocy-anin. The model predicts that an excited electron from chlorophyll will have enough energy to traverse the membrane if carotenoids are present. 

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