AP BIOLOGY

Detailed explanation-1: -Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen.

Detailed explanation-2: -Light-dependent reactions happen in the thylakoid membrane of the chloroplasts and occur in the presence of sunlight. The sunlight is converted to chemical energy during these reactions.

Detailed explanation-3: -Detailed Solution. The correct answer is option 3 i.e. Thylakoids. Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. Thylakoids are the site of the light-dependent reactions of photosynthesis.

Detailed explanation-4: -In particular, their three membranes divide chloroplasts into three distinct internal compartments: (1) the intermembrane space between the two membranes of the chloroplast envelope; (2) the stroma, which lies inside the envelope but outside the thylakoid membrane; and (3) the thylakoid lumen.

Detailed explanation-5: -The light-dependent reactions use light energy to make two molecules needed for the next stage of photosynthesis: the energy storage molecule ATP and the reduced electron carrier NADPH. In plants, the light reactions take place in the thylakoid membranes of organelles called chloroplasts.