[Campbell Biology P.249] Which of the following statements accurately describes a key differ... | Practice Question

Which of the following statements accurately describes a key difference in ATP synthesis between chloroplasts and mitochondria, as described in the text?

  • A: In chloroplasts, ATP is synthesized in the intermembrane space, while in mitochondria, it's in the stroma.
  • B: The proton gradient in chloroplasts is established across the thylakoid membrane, while in mitochondria, it's across the inner mitochondrial membrane.
  • C: ATP synthesis in chloroplasts occurs as H+ moves from the stroma to the thylakoid space, whereas in mitochondria, H+ moves from the matrix to the intermembrane space.
  • D: Chloroplasts use only light energy for ATP synthesis, while mitochondria use only chemical energy.

Explanation

The text clearly states that in chloroplasts, the H+ reservoir high H+ concentration is the thylakoid space and ATP is synthesized as H+ diffuses back to the stroma through ATP synthase across the thylakoid membrane. In mitochondria, the H+ reservoir is the intermembrane space, and ATP is synthesized as H+ diffuses back to the matrix through ATP synthase across the inner mitochondrial membrane.