AP BIOLOGY

Detailed explanation-1: -– The Hydrogen and the electrons from NADPH are used to build sugars. A large number of H+ ions accumulate in the thylakoid space as a result of photolysis and electron transport. This creates a concentration gradient across the thylakoid membrane. – The thylakoid space has more Hydrogen than the stroma.

Detailed explanation-2: -The hydrogen ions are allowed to pass through the thylakoid membrane through an embedded protein complex called ATP synthase. This same protein generated ATP from ADP in the mitochondrion.

Detailed explanation-3: -Why do hydrogen ions flow from the thylakoid space to the stroma through ATP synthase? A. They are pumped actively through ATP synthase. This uses up ATP energy and causes the production of ADP and phosphate.

Detailed explanation-4: -Protons flow down their concentration gradient into the matrix through the membrane protein ATP synthase, causing it to spin (like a water wheel) and catalyze conversion of ADP to ATP.