Final answer:
The Calvin cycle is an essential set of reactions in plants and some bacteria that converts CO₂ into organic compounds using the enzyme RuBisCO during three stages: fixation, reduction, and regeneration.
Step-by-step explanation:
The Calvin cycle is a sequence of reactions that occur in the stroma of chloroplasts in plants and some bacteria. It can be divided into three stages: fixation, reduction, and regeneration.
During the fixation stage, the enzyme RuBisCO facilitates the incorporation of CO₂ into an organic molecule, namely ribulose bisphosphate (RuBP). The next stage is the reduction phase, where the energy from ATP and reducing power of NADPH, both generated from the light-dependent reactions of photosynthesis, are used to convert 3-phosphoglycerate (3-PGA) into glyceraldehyde-3-phosphate (G3P).
Some G3P molecules leave the cycle to be used in the synthesis of various carbohydrates, while the rest are utilized in the regeneration stage to produce RuBP, thus enabling the cycle to continue fixing carbon. This complex series of reactions is essential for the conversion of inorganic carbon dioxide gas into organic carbon compounds such as glucose, which is vital for the growth and energy requirements of the plant.