Cyclic and Non-Cyclic Photophosphorylation and Photosystems

Credit to:

http://www.s-cool.co.uk/a-level/biology/photosynthesis/revise-it/light-dependant-reactions

and

http://www.s-cool.co.uk/a-level/biology/photosynthesis/revise-it/pigments-and-the-absorption-of-light

for explaining this so well and in a way that is easy to understand for an A2 Biology student