In the light-dependent reactions of photosynthesis, how do hydrogen ions get back into the stroma?
A) passive diffusion directly across the thylakoid membrane
B) active transport across the thylakoid membrane
C) facilitated diffusion across the thylakoid membrane
D) active transport through ATP synthase
E) passive diffusion through ATP synthase

Question

Quizplus · Accepted Answer

Hydrogen ions move back into the stroma through ATP synthase by facilitated diffusion, a process driven by the proton gradient across the thylakoid membrane. This movement does not require additional energy input (hence "passive") and is essential for ATP production during photosynthesis.

In the Light-Dependent Reactions of Photosynthesis, How Do Hydrogen Ions