The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find?

Question

Quizplus · Accepted Answer

The pH within the thylakoid is lower (more acidic) than that of the stroma or cytosol. This is because the thylakoid is the site of the light-dependent reactions of photosynthesis, which involve pumping protons (H+) into the thylakoid space, creating a lower pH. The pH gradient formed across the thylakoid membrane is then used to generate ATP via chemiosmosis. The stroma and cytosol have a higher pH because they are not involved in this proton pumping process.

The PH of the Inner Thylakoid Space Has Been Measured