Final answer:
NADPH drives the light-independent reactions, also known as the Calvin cycle, by providing high-energy electrons and a proton necessary for carbon fixation. It is not a form of ATP but a separate energy-carrying molecule formed during the light-dependent reactions of photosynthesis.
Step-by-step explanation:
The question asks which statements regarding NADPH are true. Here is the clarification:
- A: NADPH indeed drives the light-independent reactions, often referred to as the Calvin cycle. In this process, NADPH provides the necessary reduction potential to convert carbon dioxide into glucose.
- B: NADPH does not carry radiant energy; instead, it carries high-energy electrons and a proton, which are used in the reduction reactions during the Calvin cycle.
- C: This statement is incorrect; NADPH is not an energized form of ATP. They are both forms of chemical energy, but they are distinct molecules with different roles in cellular metabolism.
- D: High-energy electrons from the light-dependent reactions along with a proton (hydrogen ion) are indeed used to form NADPH in a process facilitated by the enzyme NADP+ reductase.
The correct selection thus includes statements A and D, indicating that NADPH is crucial for the energy transfer in photosynthesis, particularly for the light-independent reactions where sugars are synthesized.