AP BIOLOGY

Detailed explanation-1: -The light reaction occurs in the thylakoid membrane of organelles called chloroplasts in plants.-Chlorophyll in the Photosystems I and II retain a light, which triggers the arrival of high energy electrons (photoactivation).

Detailed explanation-2: -Light energy is harnessed in Photosystems I and II, both of which are present in the thylakoid membranes of chloroplasts.

Detailed explanation-3: -Photosystem I and photosystem II are the two multi-protein complexes that contain the pigments necessary to harvest photons and use light energy to catalyse the primary photosynthetic endergonic reactions producing high energy compounds.

Detailed explanation-4: -The key difference between both the photosystems – Photosystem I and photosystem II is that PS I tends to absorb light of longer wavelengths > 680nm, whereas PS II absorbs light of shorter wavelengths <680 nm.

Detailed explanation-5: -Photosystem II is located in the thylakoid membranes of chloroplasts. Photosystem II, photosystem I, and the components of the photosynthetic electron transport chain are intrinsic proteins of the thylakoid membranes of the chloroplast.