Light Dependent Rn Flashcards
1
Q
Occur on?
A
Thylakoid membranes
2
Q
Non-cyclic photophosphorylation
-light drives (pdts)
A
Synthesis of
- NADPH
- ATP
3
Q
Outline the process (non-cyclic photophosphorylation)
A
- Excited electrons from I and II reduced the Pri e acceptor
- I and II oxidised to become positively-charged
- e from photolysis of water replace e lost in PSII
- H+ and O2 are released - e from PSII, accepted by pheophytin are passed down through a chain of progressively lower energy e carriers
- at the same time, e carriers pump H+ from stroma into thylakoid space
- > accumulation for proton gradient - The e replace the e lost in PSI
- Proton diffuse from thylakoid space into stroma via stalked particle
- e from PSI passed down through a chain of progressively lower energy e carriers and accepted by NADP
4
Q
How is ATP formed?
A
- Excited e travel downhill the energy from one e to another in ETC
- Energy loss is coupled with ATP formation @chemiosmosis
- > energy derived from Proton gradient is used to drive ATP synthase to catalyse the formation of ATP from ADP+Pi
5
Q
Cyclin photophosphorylation occurs when
A
- Lack of water to supply the high energy e to replace e lost in PSII
- Lack of CO2 to re-oxidise NADPH to NADP* for non-cyclic
6
Q
Cyclic photophosphorylation
A
- Excited e from PSI that are accepted by Pri e acceptor are recycled back to PSI via another ETC involving ferredoxin
- As e pass down ETC, their excitation energy is coupled to ATP production
7
Q
NADP refers to?
A
NADP+
NADPH
8
Q
2 roles of NADP+
A
- coenzyme, final e- acceptor in ETC during non-cyclic P
2. combines with e- from PSI and H+ from photolysis of water, forming NADPH
9
Q
3 roles of NADPH
A
- carry high energy e- and H+ from light dependent rn to Clavin cycle
- intermediate energy carrier that transfer energy harnessed from light to processes utilising energy in C fixation
- utilised in Calvin cycle for reduction of GP to G-3-P; regeneration of NADP+
