AP BIOLOGY

Detailed explanation-1: -The electrons travel through the chloroplast electron transport chain to photosystem I (PSI), which reduces NADP+ to NADPH. The electron transport chain moves protons across the thylakoid membrane into the lumen.

Detailed explanation-2: -ATP synthase in thylakoids generates ATP using the proton gradient. Excited electrons from Photosystem I are used to reduce NADP.

Detailed explanation-3: -The light reactions of photosynthesis use energy from photons to generate high-energy electrons. These electrons are used directly to reduce NADP+ to NADPH. NADPH is a relatively stable molecule and can pass on its hydrogen atom to other molecules in chemical reactions. The process by which NADP+ is reduced to NADPH.

Detailed explanation-4: -Excited electrons move along the electron transport chain and are ultimately used to reduce NADP+, producing NADPH. The energy from the electrons is used to pump protons into the thylakoid lumen.

Detailed explanation-5: -The reaction center chlorophyll of photosystem I transfers its excited electrons through a series of carriers to ferrodoxin, a small protein on the stromal side of the thylakoid membrane. The enzyme NADP reductase then transfers electrons from ferrodoxin to NADP+, generating NADPH.