Photosynthesis (Exam 2) Flashcards
photosystems =
reaction centers
photosystems have
light harvesting complexes (proteins + pigments)
trap chlorophylls in photosystems
p680 (ps2) & p700 (ps1)
shape of p680 & p700
dimers
p680 & p700 have what pigment
chl a
(in p680 & p700) the numbers mean
’s of peak absorption
photosystems occur in
thylakoid membrane (inner membrane space)
electron donor in ps2
via
H2O
via H2O splitting complex
are photosystems light dependent or independent?
light dependent
electrons pass from (p680 in) ps2 to –>
plastoquinone (PQ)
plastoquinone (PQ) is an
electron acceptor
plastoquinone (PQ) can. accept
2 e- @ a time
plastoquinone (PQ) takes electrons to –>
cytochrome complex b6f
after cytochrome complex 66f, electrons go to –>
plastocyanin (PC)
cytochrome complex 66f creates
a proton H+ gradient (drives protons into intermembrane space)
plastocyanin (PC) is an
electron acceptor
electrons pass from plastocyanin (PC) to –>
p700 in ps1
electrons pass from ps1 to –>
Ferrodoxin (FD)
electrons pass from Ferrodoxin (FD) to –>
NADP+ reductase
NADP+ reductase makes
NADPH
how does cytochrome complex 66f create a proton gradient?
energy lost between p680 & p700 is used to move H+ protons from the stroma to the innermembrane space
the movement of electrons in photosynthesis is
noncyclic
NADPH then goes to
the Calvin cycle
H+ protons form the inner membrane go to –>
to ATP Synthase & back out (to go through cytochrome complex again)
water donates
& byproduct
electrons & 2 protons
byproduct = oxygen
For every H2O split =
1 NADP+ made
