Biology · PHOTOSYNTHESIS IN HIGHER PLANTS

According to the chemiosmotic hypothesis, what is the crucial topological difference in proton accumulation during ATP synthesis between chloroplasts and mitochondria?

1. A
   Protons accumulate in the chloroplast stroma, whereas in mitochondria they accumulate in the matrix.
2. B
   Protons accumulate on the outer chloroplast envelope, whereas in mitochondria they accumulate within cristae lumens.
3. C
   In chloroplasts, protons accumulate inside the thylakoid lumen, whereas in mitochondria, protons accumulate in the intermembrane space.
4. D
   In chloroplasts, protons are consumed without forming any gradient, whereas in mitochondria a steep gradient develops across the outer membrane.