photosynthesis 2 Flashcards
in photosystem 1 what does light induce
a charge seperation at p700 that forms a cation which is reduced by electron from plastocyanin
what does the electron from p700 reduce
reduces chlA0, quinone A1 and the 3 iron sulfur clusters and then eventually reduces ferredoxin
what is ferreodoxin
it is a small 2 iron sulfur cluster containing protein
what does ferredoxin do
it donates electrons to ferredoxin-NADP+ reductase which converts NADP+ to NADPH
when does cyclin electron transport occur in chloroplasts
when reducing power is plentiful but ATP is limiting
what drives ATP synthesis in chloroplasts
pH gradient
how is energy transferred
it is transferred between adjacent pigment molecules by resonance energy transfer
describe what happens in resonance energy transfer
through electromagnetic interactions through space the excitation energy can be transferred to electrons in adjacent molecules
how does the reaction centre complex act as an energy trap or funnel
because it can absorb longer wavelength
what are carotenoids
isoprenoid compounds derived from geranyl geranyl PP.
under high light intensity they help protect from oxidative damage.
what is LHC-II
light harvesting protein associated with PSII. each polypeptide binds 12 molecules of chla and b and several carotenoids.
is PSI monomeric
yes
where is ChlA and ChlB found
A is found in reaction centres and antenna complexes while B is only in antenna complex
is the thylakoid membrane heterogenous
yes
where are PSI AND II in the membrane
PSI and ATP synthase are in the unstacked region while PSII is in the stacked region. b6f complex is in both regions.
