[Campbell Biology P.248] To artificially induce ATP synthesis in the stroma of an isolated c... | Practice Question

To artificially induce ATP synthesis in the stroma of an isolated chloroplast, based on the principles of chemiosmosis described, how would you adjust the pH of the stroma?

  • A: Decrease the pH of the stroma to make it more acidic.
  • B: Increase the pH of the stroma to make it more alkaline.
  • C: Maintain a neutral pH in the stroma.
  • D: The pH of the stroma is irrelevant; only the pH of the thylakoid space matters.

Explanation

ATP synthesis in chloroplasts occurs as protons H+ move from the thylakoid space, where they are highly concentrated low pH , into the stroma, where they are less concentrated higher pH , through ATP synthase. To artificially induce this, the stroma needs to have a relatively high pH low H+ concentration to create or enhance the necessary proton gradient for ATP synthase to function.