Photosystems 1 and 2
through electron transport
chain
By Andrew Sanchez
and Manuel Jardine
Definitions:
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Thylakoid membrane: Contains pigments, photosystems, ATP Synthase, and an electron
transport train and is responsible for the light dependent aspect of photosynthesis
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Electron Transport Chain: A cluster of proteins that transfer electrons through a membrane
within mitochondria to make ATP
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ATP: A Molecule that stores and than releases energy in living organisms
ATP Synthase: A protein that uses energy to produce ATP
NADPH: a product of the first stage of photosynthesis and is used to help fuel the reactions that
take place in the second stage of photosynthesis.
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Ferredoxin: sulfur proteins that mediate electron transfer in a range of metabolic reactions.
Photon: a particle representing a quantum of light
Location:
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In eukaryotes, an important
electron transport chain is
found in the inner
membrane
It is also found in the
thylakoid membrane of the
chloroplast
Thylakoids look like a stack
of pancakes
Photosystem II:
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Photosystem II goes first in the process to make NADPH and
start the sugar complex
The inner core of Photosystem II is called the reaction center
P680 absorbs at 680 nanometers which is around red light
Photon will come from a light source and get absorbed by the
Light harvesting complexes
P680 then takes the electron from H20 and releases O2 and
H+
It than excited the electron and moves up in energy states into
the electron acceptor
Electron transport chain:
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Once finished with Photosystem II the
electron moves into the Electron
Transport chain
As its going down the Electron transport
chains the energy that its losing is absorbed
by ATP
Once finished passing through the Electron
Transport chain it then goes to Photosystem
I
Photosystem I:
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Photosystem I goes second in the process to
make NADPH and start the sugar complex to
make glucose
Once the Electron goes into P700 which absorbs
at 700 nanometers which is every color except
for green which gives it its color
The Electron gets more energy from another
photon which goes through the Light harvesting
complexes
Once it has enough energy it then moves up in
energy states which goes up into the electron
acceptor
It than moves into the Ferredoxin
End of process:
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The electron then moves into the Ferredoxin
To make an NADPH it has to have 2 electrons with
NADP+ with Hydrogen
With that electron it than fills up half of the NADP+
To get the other electron it has to do another process
to fill it up again to finally make a NADPH
Once it finally makes the NADPH it combines with the
ATP to create the sugar complex in than makes
Glucose