AP BIOLOGY

Detailed explanation-1: -This is accomplished by the use of two different photosystems in the light reactions of photosynthesis, one to generate ATP and the other to generate NADPH. Electrons are transferred sequentially between the two photosystems, with photosystem I acting to generate NADPH and photosystem II acting to generate ATP.

Detailed explanation-2: -Photosynthesis occurs in two stages. During the first stage, the energy from sunlight is absorbed by the chloroplast. Water is used, and oxygen is produced during this part of the process. During the second stage, carbon dioxide is used, and glucose is produced.

Detailed explanation-3: -The ATP and NADPH from the light-dependent reactions are used to make sugars in the next stage of photosynthesis, the Calvin cycle. In another form of the light reactions, called cyclic photophosphorylation, electrons follow a different, circular path and only ATP (no NADPH) is produced.

Detailed explanation-4: -Three ATP molecules will be made, provided photosystem I recycles one electron in order to contribute two protons to the proton motive force.

Detailed explanation-5: -The light-dependent reaction is a photochemical reaction taking place in the thylakoid membranes of chloroplasts, where light energy is transformed into adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH).