Bacterial Photosynthesis
Lecture 9‹header›
Fig. 5.23c
Reactions involved in Photosynthesis
Light reactions or phase:
Oxygenic- ATP and NAD(P)H
Anoxygenic- purple primarily ATP; greensulfur/heliobacteria can generate ATP and reducing
power
Dark reactions or phase: CO2 fixation
Calvin Benson Cycle (C3 pathway, photosynthetic
carbon cycle, reductive pentose phosphate pathway)
Reverse (reductive) Krebs (TCA) cycle
Hydroxypropionate pathway
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Bacterial Photosynthesis
Lecture 9‹header›
Isoprenoids:
Tetrapyrroles:
β-carotene (carotenoid)
Bile pigments
cyanobacteria
red algae
phycobiliproteins
phycobilisomes
Primary function: photoprotective role
Fig. 17.8
Fig. 17.10
Tetrapyrrole: Porphyrins
Phycobilisome
succinyl-CoA
Fig. 17.3a
Fig. 17.10b
Plants, algae, cyanobacteria Purple, green-sulfur, heliobacteria
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Bacterial Photosynthesis
Lecture 9‹header›
Arrangement of light-harvesting
chlorophylls/bacteriochlorophylls
Chloroplast
excitons
Antenna pigments
Complexes of 50300 molecules
Reaction center chlorophylls/bacteriochlorophylls
Fig. 17.6
Bacterial Photosynthetic Apparatus
Fig. 17.5
Chlorosome of Green-sulfur Bacteria
heliobacteria
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Bacterial Photosynthesis
Lecture 9‹header›
Electron Flow in Purple Bacteria
Organization of ecarriers in purple bacteria
eBacteriopheophytin
Anoxygenic photosyn.
one photosystem
(purple)
Fig. 17.4
Fig. 17.15
Electron Flow in Purple Bacteria
H2---> NAD(P)H
hydrogenase
NADH
Lactate or
succinate (e-)
Anoxygenic
Photosynthesis (purple)
Fig. 17.4
(H2S, So, S2O3-2,
Fe+2) H2
H2S ---> So
S2O3-2---> SO4-2
Fig. 17.18
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Bacterial Photosynthesis
Lecture 9‹header›
Oxygenic Photosynthes
\
Fig. 17.19
Calvin-Benson Cycle
Ribulose bisphosphate
carboxylase (RubisCO)
phosphoribulokinase
Fig. 17.22
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