Final answer:
The primary function of the Calvin Cycle is to convert carbon dioxide into carbohydrates using ATP and NADPH. This process is known as carbon fixation.
Step-by-step explanation:
The primary function of the Calvin Cycle is to convert carbon dioxide from the atmosphere into carbohydrates using the energy and reducing power of ATP and NADPH. This process is known as carbon fixation, where inorganic CO₂ is converted into organic compounds. The cycle uses the energy from ATP and NADPH to regenerate a molecule called RuBP, which is necessary for the cycle to continue.