Which molecule transports high-energy electrons during the process of photosynthesis?

NADPH is the molecule that transports high-energy electrons during photosynthesis. It plays a critical role in the light-dependent reactions, where light energy is converted into chemical energy. In these reactions, chlorophyll absorbs sunlight, which energizes electrons and allows them to be transferred through a series of proteins in the thylakoid membrane, eventually leading to the reduction of NADP+ to form NADPH. This high-energy electron carrier is then used in the Calvin cycle, where it provides the reducing power necessary for the conversion of carbon dioxide into glucose.

ATP also participates in photosynthesis by providing energy, but it does not transport high-energy electrons in the same manner as NADPH. RuBP is a five-carbon sugar that acts as a carbon dioxide acceptor in the Calvin cycle, while glucose is the end product of photosynthesis but does not directly play a role in transporting electrons during the light reactions. Thus, NADPH is uniquely suited for this function as it directly carries and donates high-energy electrons needed for the synthesis of carbohydrates.