Photosynthesis

Question 1

What three factors maintain the proton gradient between the thylakoid space and the stroma?

Answer 1

• Proton pump associated with ETC pushing protons into thylakoid space
• photolysis of water in the thylakoid space
• removal of protons in the stroma from reducing NADP

Question 2

How does Cyclic photophosphorylation work?

Answer 2

• PSI absorbs photons which excites electrons in the chlorophyll a molecules in its reaction centre
• there are emitted and picked up by an electron acceptor which passes them down a chain of electrong carriers back to PSI