Question

Which of the following statements must be true in order for ATP synthase present in chloroplasts to function properly?

Answer 1

Answer;

b. the pH of the stroma must be higher than the pH of the thylakoid lumen

Explanation;

• Energy from an electron transport chain is used to actively transport protons from the stroma to the thylakoid lumen. Thus the lumen has a relatively higher proton concentration and therefore a lower pH than the stroma.
• Higher [H+] means lower pH, while Lower [H+] means higher pH. During the process of photosynthesis, the lumen becomes acidic, as low as pH 4, compared to pH 8 in the stroma.