What is phosphorylation in photosynthesis?

2 Answers

Addition of high energy phosphate to ADP to form ATP is called Phosphorylation. In Photosynthesis it occurs in presence of sunlingt and is called as Photophosphorylation

Sep 1, 2016

The phosphorylation ( addition of phosphate ) of ADP to ATP during photosynthesis is called as photophosphorylation.

Explanation:

Light energy trapped during photosynthesis, powers this reaction.

A proton gradient and electrical charge is built up in the thylakoid membranes. This occurs as a result of electron flow during the light reaction , which provides energy to drive the synthesis of ATP from ADP and inorganic phosphorus.

Photophosphorylation occurs in two ways :

1) Noncyclic photophosphorylation
Cytochrome b6f ( enzyme ) uses the energy of electrons from Photosystem (II) to create a proton gradient across the thylakoid membranes. ATP synthatase ( enzyme) uses this energy to form ATP.

2) Cyclic photophosphorylation
In this process cytochrome b6f ( enzyme ) uses energy of electrons from Photosystem (I) and (II) , to create more ATP. It also maintains the right proportion of NADPH for light reaction.

Photosystem (I) and (II) are protein complexes that absorb photons and use their energy.