Question

Differences between photophosphorylation (PP) and oxidative phosphorylation (OP) is
A. In PP, synthesis is of ATP while in OP it is of ADP
B. In PP, oxygen is evolved while in OP oxygen is taken up
C. Both cannot take place in light
D. PP can take place in green leaves while OP cannot occur in green leaves

Answer 1

Hint: Photophosphorylation is a process of producing ATP molecules from ADP which is done during the process of photosynthesis and OP occurs during cell respiration.

Complete answer:
First of all, you should know about PP and OP. Photophosphorylation is a process which is done in photosynthesis where there is conversion of ADP into ATP by using the energy from sunlight. Oxidative photophosphorylation is a process where there is formation of ATP and the cells use enzymes in this process to oxidise nutrients.
If we look at options now, Option A is In PP, synthesis is of ATP while in OP it is of ADP. In PP and OP both, there is formation of ATP not ADP but in the option, it says there is formation of ADP in OP which is wrong. So, this option is incorrect as in the question, difference is asked between PP and OP and this is not their difference since in both the processes there is synthesis of ATP. Therefore, it gets eliminated.
Moving to option B which is In PP, oxygen is evolved while in OP oxygen is taken up. This statement is correct that oxygen is evolved in the photophosphorylation whereas in oxidative photophosphorylation, oxygen is taken up. Therefore, this option is the correct one as this is the difference between PP and OP.
Moving to option C which is Both cannot take place in light. This option is incorrect since this is the similarity not difference but in the question difference between PP and OP has been asked. Therefore, this option gets eliminated.
Last option D is PP can take place in green leaves while OP cannot occur in green leaves. This option is incorrect since both these processes can occur in green leaves but in the question difference is asked. Therefore, it gets eliminated.

Thus, the correct answer is option B which is In PP, oxygen is evolved while in OP oxygen is taken up.

Note:
In both PP and OP, there is formation of ATP and PP occurs during photosynthesis whereas Op occurs during cell respiration. In PP, oxygen is evolved whereas in OP, oxygen is taken up and that is the difference between both the process which makes option B the correct one.