[Campbell Biology P.248] Which of the following statements correctly highlights a key differ... | Practice Question

Which of the following statements correctly highlights a key difference between chemiosmosis in chloroplasts and mitochondria?

  • A: Chloroplasts derive high-energy electrons from organic molecules, while mitochondria derive them from water.
  • B: Chloroplasts use light energy to drive ATP synthesis, while mitochondria use chemical energy from food molecules.
  • C: Both organelles pump protons from a region of high H+ concentration to low H+ concentration.
  • D: ATP synthase is only found in chloroplasts, not in mitochondria.

Explanation

The text states that in chloroplasts, photosystems capture light energy to drive electrons from water, leading to ATP synthesis photophosphorylation . In mitochondria, chemical energy from food molecules is used to drive electrons, leading to ATP synthesis oxidative phosphorylation . This is a fundamental difference in their energy sources for ATP production.