Question

Which one occurs both during cyclic and non-cyclic modes of photophosphorylation?

• A. Involvement of both PS-I and PS-II
• B. Formation of ATP
• C. Release of $O_2$
• D. Formation of NADPH

Answer 1

The correct option is B Formation of ATP

Cyclic photophosphorylation is a type of light energised ATP synthesis in which electron, expelled by excited photocentre is returned to it after passing over a chain of electron carriers. Photolysis of water does not take place.
Non-cyclic photophosphorylation is the type of light energised ATP synthesis in which electron expelled by excited photo centre does not return to them. It involves two photochemical Systems (PS-I and PS-II) and produces assimilatory power (ATP and NADPH). Photolysis of water takes place and oxygen is released as a byproduct.
Thus, ATP formation is the only process that occurs in both cyclic and non-cyclic photophosphorylation.