Question

differentiate b/w photophosphorylation and oxidative phosphorylation

Answer 1

Differences between oxidative phosphorylation and photophosphorylation are as follows:

Oxidative phosphorylation	Photophosphorylation
It is the mechanism of ATP synthesis during the process of respiration.	It is the mechanism of ATP synthesis during the process of photosynthesis
Presence of sunlight is not required	It occurs in presence of sunlight
It occurs in Mitochondrion	It occurs in chloroplast
In this process, proton gradient across the membrane is used to synthesise ATP from ATP synthase similar to photophosphorylation, but protons accumulate in the intermembrane space of the mitochondria when electrons move through the ETS	Proton accumulation occur towards the inside of the membrane, i.e., in the lumen
The energy of oxidation-reduction is utilised for the production of proton gradient needed for the synthesis of ATP this is why this process is called oxidative phosphorylation.	Light energy that is utilised for the production of proton gradient required for phosphorylation
FADH2 and NADPH act as electron donor and Oxygen act as electron acceptor so, H2O is released as bioproduct	Water act as electron donor and so oxygen is released as biproduct; NADP+ act as electron acceptor
In this only ATP is produced utilising NADPH and FADH2	It is of two types depending upon the type of photosystems involved * Noncyclic photophosphorylation* Cyclic photophosphorylationNoncyclic photophosphorylation yields both ATP and NADPH and involves both photosystems- (PSI) and (PSII) .Cyclic photophosphorylation yields only ATP and involves only one photosystem (PSI).