Question

Describe photosystem-I and photosystem-II in green plants. How these photosystems
co-operate in producing NADPH and ATP in light reactions of photosynthesis?

Answer 1

Photosystem II is the first link in the chain of photosynthesis. It captures photons and uses the energy to extract electrons from water molecules. First, when the electrons are removed, the water molecule is broken into oxygen gas, which bubbles away, and hydrogen ions, which are used to power ATP synthesis. Photosystem I (PSI, or plastocyanin-ferredoxin oxidoreductase) is the second photosystem in the photosynthetic light reactions of algae, plants, and some bacteria. Photosystem I is an integral membrane protein complex that uses light energy to produce the high energy carriers ATP and NADPH.