AP BIOLOGY

Detailed explanation-1: -Photosystems are structures within the thylakoid membrane that harvest light and convert it to chemical energy. Each photosystem is composed of several light-harvesting complexes that surround a reaction center.

Detailed explanation-2: -Physically, photosystems are found in the thylakoid membranes. 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.

Detailed explanation-3: -Photosystem I (PS I) and II (PS II) are found in the thylakoid membranes inside the chloroplast. The photosystems are responsible for carrying out photochemical phase or light reaction of photosynthesis.

Detailed explanation-4: -The light-dependent reactions of photosynthesis take place within the thylakoids. These reactions occur when the pigment chlorophyll, located within the thylakoid membranes, captures energy from the sun (photons) to initiate the breakdown of water molecules.

Detailed explanation-5: -Photosystem II (or water-plastoquinone oxidoreductase) is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. It is located in the thylakoid membrane of plants, algae, and cyanobacteria.