photosynthesis hl mrs. jackie. draw the structure of a chloroplast about 2-10microm in diameter...
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Photosynthesis HLPhotosynthesis HLMrs. Jackie
Draw the structure of a Draw the structure of a chloroplast chloroplast
About 2-10microm in diameter
Include ◦Circular DNA◦Ribosomes◦Starch grains◦Fat droplets
Inter granal lamella
grana
Photosynthesis consist of light Photosynthesis consist of light dependent and light independent dependent and light independent reactionsreactions
Light dependent rx and Light dependent rx and photophosphorilationphotophosphorilation
Energy level
PSII
H2O
2H++1/2O2
light
X
PSI
light
2e-
2e-
2e-
2e-
ADP +Pi
ATP
ADP +Pi
ATP
y
2e-
NADPHNADP +H
Non-CyclicPhotophosphorilation
Non cyclic photophosphorylationNon cyclic photophosphorylation
Light hits the pigments on PSII which are mainly found in the grana
Chlorophyll a involved absorbing light at the 680nm
Light absorption excites the electron which move to electron acceptor X.
Chlorophyll mol change to a positive because it looses e-.
The electrons are passed thorough a series of redox reactions to PSI
Non cyclic photophosphorylationNon cyclic photophosphorylation
The presence of Chl a+ induce the lysis of water so that oxygen, H and electrons are released
Electrons are taken by Chl a+ which turns into Chl a
The oxygen is released as a waste productThe H are pumped to the lumen of the
grana and accumulate until diffusion occurs though the channel of the APT synthethase and ADP +Pi are converted into ATP
Grana Thylakoid membraneGrana Thylakoid membrane
Lumen
ATP
ADP+ Pi
H+
light
2e-
NADP+H2e-
H+
H2O2H+1/2O2
Non-cyclic photophosphorilationNon-cyclic photophosphorilation
The light also hits the photosystem I which absorbs light at 700nm.
Electrons move away from the nucleus.Electrons move away from chl a to the
electron acceptor YElectron are then passed on to NADP
which combines with H to produced NADPH
The chl a+ receive electrons from the electron carrier chain and become chl a
Cyclic photophosphorilationCyclic photophosphorilation
Increasin energy level
X
Y
PSI
2e-
2e-
2e-
2e-
ADP +Pi ATP
ADP +Pi ATP
light
Light independent reactionsLight independent reactions
Calvin Cycle◦Takes place in the
stroma of the chloroplast
◦ATP provides energy and NADPH provides the reducing power needed for biosynthesis using CO2
◦RuBP- carbon dioxide acceptor
Calvin CycleCalvin Cycle
6 Glycerate-3-phosphate(GP) (6x3C)
6 Glycerate-1,3-diphosphate(6 x 3C)
6 triose-phosphate(TP) (6 x3C)
5 Triose-phosphate(TP) (5x3C)
3 Ribulosebiphosphate(RuBP) (3x5C)
3CO2(3X1C)
RuBP carboxylase
6ADP +6Pi
6ATP
6NADPH
6NADP+
1TP (1x3C
3ADP+3Pi
3ATP
Review of Calvin CycleReview of Calvin Cycle
The Calvin Cycle takes place in the stoma of the chloroplast.
RuBP take up CO2 with the aid of RuBP carboxylase forming GP (glycerate 3 phosphate)
GP will be reduced to TP (triose-phosphate) but this conversion needs energy from ATP and reducing power from NADPH.
TP can be converted to glucose, sucrose, starch, fatty acids and amino acids
TP is also converted to RuBP to keep the cycle going. This process requires ATP