Which one of the following products diffuses out of the chloroplast during photosynthesis?
- ADP
- NADPH
- O2
- ATP
Answer
(3) O2
Solution
O2 is released by photolysis of water in the light reaction; being a small gaseous by-product it diffuses out of the chloroplast (and out of the leaf).
ATP and NADPH are used inside the stroma in the Calvin cycle, and the ADP and NADP+ formed are recycled to the thylakoids.
Answer: (3)