What end product can NADPH and ATP from the light reactions be used for?

NADPH and ATP generated during the light reactions of photosynthesis play a crucial role in the subsequent stages, specifically the Calvin cycle. During the light reactions, sunlight energy is harnessed to convert water and carbon dioxide into oxygen, ATP, and NADPH.

ATP serves as an energy source, while NADPH provides reducing power, which is necessary for the conversion of carbon dioxide into glucose. In the Calvin cycle, these molecules facilitate the fixation of carbon into organic compounds, ultimately leading to the synthesis of glucose and other carbohydrates. This process is essential for energy storage in plants and provides the foundation for the food chain.

Other options do not accurately represent the primary function of NADPH and ATP produced in the light reactions. For instance, oxidizing glucose during respiration is a process that occurs later in cellular metabolism, while the buildup of H+ ions is part of the mechanism that generates ATP, but it is not the end product application for NADPH and ATP. Additionally, the formation of chlorophyll molecules is not directly powered by ATP and NADPH in the Calvin cycle. Therefore, the correct answer emphasizes the integral role of NADPH and ATP in driving the Calvin cycle for sugar synthesis.