LIFE SCIENCE

Detailed explanation-1: -1: Photosystem I I: In the photosystem II (PSII) reaction center, energy from sunlight is used to extract electrons from water. The electrons travel through the chloroplast electron transport chain to photosystem I (PSI), which reduces NADP+ to NADPH .

Detailed explanation-2: -Here are the basic steps: Light absorption in PSII. When light is absorbed by one of the many pigments in photosystem II, energy is passed inward from pigment to pigment until it reaches the reaction center. There, energy is transferred to P680, boosting an electron to a high energy level.

Detailed explanation-3: -In photosystem II, enzymes absorb the photons of light to energise the electrons. The energised electrons then travel through a series of cofactors and coenzymes to reduce plastoquinone to plastoquinol. The energised electrons also replace the oxidising water to form molecular oxygen and hydrogen ions.

Detailed explanation-4: -There are two kinds of photosystems: photosystem I (PSI) and photosystem II (PSII) (Fig. 3.3). PSII acts first during the light transformation process in photosynthesis, but it was named PSII because it was discovered second.