+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
Green and purple bacteria differ from
|
Cyanobacteria and eucaryotic photosynthesizers in several fundamental ways
|
|
In particular green And purple bacteria do Not use
|
Water as an electron source or produce O2 photosynthetically
|
|
That means they are
|
Anoxygenic
|
|
In contrast Cyanobacteria and eukaryotic photosynthesizers are always
|
Oxygenic
|
|
NADPH is not directly produced in the
|
Photosynthetic light reaction of purple bacteria
|
|
Green bacteria can reduce
|
NAD+ during light reaction
|
|
To synthesize NADH and NADPH green and purple bacteria must use electron donors like
|
Hydrogen hydrogen sulphide element sulphur and organic compounds that have more reduction potential than water and easier to oxidize
|
|
Green and sulphur bacteria possess slightly different photosynthetic pigments callled
|
Bacteriochlorophylls
|
|
It has absorption maxima at
|
Longer wave lengths
|
|
Bacteriocholrophylls a and b have maxima in either at
|
775 and 790 nm respectively
|
|
In vivo maxima are about
|
830nm to 890nm (bacteriocholorophyll a)
|
|
And in bacteriocholrophyll b maxima are about
|
1020nm to 1040nm
|
|
There are 4 groups of green and purple photosynthetic bacteria
|
Each containing several genera :green sulphur bacteria (cholorobium) green non sulphur bacteria (cholroflexus) purple sulphur bacteria (chromatium)purple non sulphur bacteria(rhodospirillum,rhodopseudomonas)
|
|
Many difference found in green and purple bacteria are due to lack of
|
Photosystem II
|
|
They cannot use water as an electron donor in
|
Non cyclic electron transport
|
