1. Photosynthesis 2: Energy conversion and electron conduction in soft matter
Electron flow in photosynthesis of cyanobacteria H+
ADP
ATP
cytoplasm
Q/QH2/Q hn
ATPase
bc1 RC
LH-II
LH-I
periplasm e- H+
cytochrome c2
Electron flow in photosynthesis of purple bacteria

2. Electron flow in photosynthesis of cyanobacteria and Plants
backward direction: respiration = food consumption in mammals
From Nature 411, (2001) 897, W. Kuhlbrandt.

3. Photosynthesis 2: Energy conversion and electron conduction in soft matter
Electron flow in photosynthesis of cyanobacteria H+
ADP
ATP
cytoplasm
Q/QH2/Q hn
ATPase
bc1 RC
LH-II
LH-I
periplasm e- H+
cytochrome c2
Electron flow in photosynthesis of purple bacteria

4. Role of Thermal Disorder on Electron Transfer in the Photosynthetic Reaction Center
is coupled to the thermal motion of the
surrounding protein.

5. Particle – Hole Separation in the Reaction Center and Solar Cells
protein
protein rotated – 900 and stretched

6. Cytochrome c2 docking hn H+ ADP ATP cytoplasm Q/QH2/Q ATPase bc1 RC
LH-II
LH-I
periplasm e- H+
cytochrome c2

7. Photosynthetic Apparatus of Purple Bacteria
Very Large Conformational Changes Qo
2Fe2S e-
cyt c1
two path-
ways for
oxidation
of Qo
site
Iron Sulfur
Protein
head rotation
can redirect
2nd electron
Sergei Izrailev

8. Photosynthetic Apparatus of Purple Bacteria
Very Large Conformational Changes F1
rotatory catalysis
(twist
conformational change
ATP synthesis ) F1 s t a l k
(from Wang & Oster)
elastomechanical
coupling F0
ATP synthase
energy transformation
(proton motive force
rotation)
(Walker, Whilce,
Fillingame)

9. Photosynthetic Pathway in
Cyanobacteria and Plants

10. Electron Carrying Molecules
bacterio-
chlorophyll
chain
chain
bacterio-
pheophytin
ubiquinone
chain

11. Particle – Hole Separation in the Reaction Center and Solar Cells
protein
protein rotated – 900 and stretched

12. The energy gap is Gaussian distributed

13. Two State QM System Coupled to Protein Matrix
First case: Coupling to a single oscillator
Hamiltonian
Protein matrix is a bath of oscillators linearly
coupled to the electron transfer according to
only a single oscillator considered at present!

14. Two State QM System Coupled to Protein Matrix
Second case: Coupling to an ensemble of oscillators
Hamiltonian
Protein matrix is a bath of oscillators linearly
coupled to the electron transfer according to

15. Electron Transfer Process Coupled to the Protein Matrix
Rate for an ensemble of oscillators
Relaxation rate
But we don’t know all the coupling constants cj ? All we need to know is

16. Solution of Rate Equation

17. Electron Transfer Process Coupled to the Protein Matrix
Rate for an ensemble of oscillators
Relaxation rate
But we don’t know all the coupling constants cj ? All we need to know is

18. Electron Transfer Process Coupled to the Protein Matrix
Relaxation rate
1994
energy gap
energy gap correlation function
rms deviation of energy gap

19. Temperature Dependence of Electron Transfer Rate