In the Calvin cycle, the reducing power from NADPH is used during:

Explanation

In the Calvin Cycle, the reducing power from NADPH is used during the reduction phase of the cycle. The Calvin Cycle, also known as the light-independent reactions of photosynthesis, takes place in the stroma of chloroplasts and is responsible for the synthesis of carbohydrates, primarily glucose. During the Calvin Cycle, the reducing power in the form of NADPH, which was generated during the light-dependent reactions (photophosphorylation), is utilized to reduce 3-phosphoglycerate (3-PGA) to glyceraldehyde-3-phosphate (G3P). This reduction phase involves a series of enzyme-catalyzed reactions, and the NADPH donates electrons to convert 3-PGA into G3P.