Question

Synthesis of $ADP+Pi⟶ATP$ in grana/photosynthesis is

• A. Phosphorylation
• B. Photophosphorylation
• C. Oxidative phosphorylation
• D. Photolysis

Answer 1

Answer: (B)

Photophosphorylation

Photophosphorylation is the process in which light energy is converted into chemical energy through the production of ATP. It is the process of formation of ATP from ADP and inorganic phosphate (IP) utilizing light energy. It occurs in grana of chloroplast during photosynthesis. The process of reduction of $NADP$ into $NADP+H^{+}$ may be denoted as electron transport system (ETS). The flow of electrons through ETS is linked to photophosphorylation. Electron transport chain is a series of electron carriers over which electrons pass in a downhill journey releasing energy at every step that is used in generating an electrochemical proton gradient which helps in synthesizing ATP. Based on the path of electrons, associated photophosphorylation can be identified as non-cyclic and cyclic phosphorylation.