Problem:
In the light, the pH of the chloroplast thylakoid lumen falls from about pH 7.0 to about pH 4.0.
Question1: Explain in one or two sentences why this is so.
Question 2: Calculate the PMF across the thylakoid membrane in the light if the stromal pH is 7.8 and the membrane electrical potential is +20 mV (lumen positive). Give units. Show your work.