Question

question 5
electrons lost from photosystem i during the light reactions are replaced by electrons from:
glucose
nadph
water
photosystem ii
atp

Explanation:

During the light reactions of photosynthesis, in non - cyclic photophosphorylation (the main pathway in plants under normal conditions), electrons lost from Photosystem I are replaced by electrons from Photosystem II. Photosystem II gets its electrons from the splitting of water, but the direct donor to Photosystem I (to replace its lost electrons) is Photosystem II. Glucose is not involved in this electron - replacement process in the light reactions. NADPH is an electron carrier (a product of the light reactions, formed when electrons are transferred to NADP+). ATP is an energy - carrying molecule (produced in the light reactions through chemiosmosis) but not an electron donor to replace electrons in Photosystem I.

Answer:

Photosystem II