Question

Write a short note on ATP formation.

Answer 1

The formation of ATP molecules (chemical energy) from ADP and $H_{3}P{O}_4$ in presence of light and chlorophyll-a during the photochemical phase of photosynthesis is called photophosphorylation.

$ADP+H_{3}P{O}_4\underset{chlorophyll-a}{\overset{light}{\to }}ATP$

Where, ADP is Adenosine Diphosphate

ATP formation takes place through the following two types of phosphorylation reactions:

(a) Non-cyclic photophosphorylation (involves both PS-I and PS-II).

(b) Cyclic photophosphorylation (involves only PS-I).