Would you expect the thylakoid lumen pH to be lower or highe

Would you expect the thylakoid lumen pH to be lower or higher during the day time relative to the night? What physiological process is responsible for the day-night difference in pH?

Solution

The thylakoid lumen pH is to be lower during the day time relative to the night because day time \"light reactions including photosynthesis\" in the presence of water predominates compared to nights result in higher photooxidation and water splitting to generate more \"proton gradient\" across the thylakoid lumen compared to the stroma finally low pH. The photosynthesis rate and light reaction & photooxiation rate of water molecules is lesser during night time and majority of stomata is closed compared to day time, where light depedent reactions are higher result day-night difference in pH. These are resulting in changes in rate of hydrogen ions are transported from the stroma to the thylakoid space