Biomedical Engineering Reference
In-Depth Information
(a)
(b)
FIGURE 22.7
(a). Photosystem. I. with. the. protein.. (b). Photosystem. I. without. the. protein.. The. complex. array. of. chlorophyll.
chromophores.can.be.visualized.
and.reaction.centers,.the.PS.I.light-harvesting.chlorophyll.molecules.are.associated.with.
the.same.protein.that.binds.the.redox.cofactors.present.in.its.reaction.center..All.pigments.
are.packed.with.high.density.and.speciic.orientation,.allowing.maximum.adsorption.of.
a. decoherent. solar. source. and. extremely. fast. hopping. of. the. excitations. throughout. the.
PS.I.network..This.excitation.energy.transfer.between.the.Chl.chromophores.occurs.in.a.
very.short.time.(200-600.fs).
19
.The.optimal.design.of.site.energies.and.orientations.of.chlo-
rophyll.molecules.in.the.reaction.center.ensures.very.eficient.excitation.dynamics.of.PS.I..
Figure 22.7.illustrates.the.complex.arrangement.of.chlorophyll.chromospheres.with.and.
without.protein.scaffolding..Without.the.protein.overlay,.one.can.see.the.complex.array.of.
chlorophyll.chromophores.
