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: -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: -Light hits the first molecule within the thylakoid called photosystem II (PSII), shown in blue-green. This causes a process called photolysis, which creates a buildup of hydrogen ions and eventually creates ATP.

Detailed explanation-4: -There are two types of photosystems in the light-dependent reactions, photosystem II (PSII) and photosystem I (PSI). PSII comes first in the path of electron flow, but it is named as second because it was discovered after PSI.

Detailed explanation-5: -A Recipe for Energy The electrons must travel through special proteins stuck in the thylakoid membrane. They go through the first special protein (the photosystem II protein) and down the electron transport chain. Then they pass through a second special protein (photosystem I protein).