AP BIOLOGY

Detailed explanation-1: -During the process, the electrons from NADPH and ATP are transferred to 3-PGA, which further gets reduced to produce G3P or glyceraldehyde-3-phosphate. Thus, ATP is providing electrons in the mentioned reaction.

Detailed explanation-2: -Reduction. In the second stage, ATP and NADPH are used to convert the 3-PGA molecules into molecules of a three-carbon sugar, glyceraldehyde-3-phosphate (G3P). This stage gets its name because NADPH donates electrons to, or reduces, a three-carbon intermediate to make G3P.

Detailed explanation-3: -Energy from ATP is used to fuel all manner of chemical reactions, including those required for copying DNA and building proteins. In these reactions, enzymes oversee the transfer of energy from ATP hydrolysis to the formation of another chemical bond.

Detailed explanation-4: -Reduction. In the second stage of the Calvin cycle, the 3-PGA molecules created through carbon fixation are converted into molecules of a simple sugar – glyceraldehyde-3 phosphate (G3P). This stage uses energy from ATP and NADPH created in the light-dependent reactions of photosynthesis.

Detailed explanation-5: -In summary, it takes six turns of the Calvin cycle to fix six carbon atoms from CO2. These six turns require energy input from 12 ATP molecules and 12 NADPH molecules in the reduction step and 6 ATP molecules in the regeneration step.