Cyclic Photophosphorylation

Question 1

What happens during cyclic phosphorylation?

Answer 1

photosynthetic pigments e.g. chlorophyll a absorbs light energy in p.s.1
this excites an electron to a higher energy level
electron flow through an electron transport chain releasing its energy
energy is used to create a proton gradient
hydrogen ions flow back to the stroma through ATP synthase
this produces energy for adp and pi to make ATP

Question 2

What is the difference between cyclic and non cyclic?

Answer 2

cyclic is only P.SI and non-cylic is PS.1 and PS.2

clyclic makes ATP only and non clyclic makes ATP, NADPH, and oxygen

cyclic - electrons are recycled and non cyclic - electrons leave P.S.1 to release NADP