Non-Cyclic Photophosphorylation / Electron Flow: Pathway 2 Flashcards
How many electrons leave the reaction centre chlorophyll in the cluster of pigments during non-cyclic photophosphorylation?
Two electrons leave the electron acceptor
What happens to the two high-energy electrons when they leave the reaction centre chlorophyll?
They are passed to an electron acceptor and then along a series of electron acceptors
Where do the events of non-cyclic photophosphorylation take place?
The grana of the chloroplast
Why is this electron flow referred to as non-cyclic?
As the energised electrons do not return to the chloroplast
Instead of retuning to the chlorophyll, what happens to the two high-energy electrons?
The two electrons combine with NADP+ to form NADP-
What happens to the electrons as they move form electron acceptor to electron acceptor?
They lose energy which is trapped by ADP and a phosphate and then used to form ATP and water
What do the electrons combine with to form NADP-?
NADP+
What is formed when the two electrons combine with NADP+?
NADP-
What combines with NADP+ to form NADP-?
2e-
To electrons
What happens after NADP- has been formed?
The chlorophyll molecule is now short of electrons so it gains new electrons from the splitting of water - photolysis
Define photolysis.
The splitting of water by light
What is formed from the splitting of 2 water molecules?
3
4H+ (four protons)
4e- (four electrons)
O2 (oxygen gas)
What happens to the protons formed by through photolysis?
They are stored in a proton pool in the chloroplast
What happens to one of the protons stored in the proton pool?
One is attracted to NADP- and combines with it to reduce it to NADPH
Give the chemical formula for the formation of NADP-.
NADP+ +2e- –> NADP-
