The second stage of the calvin cycle needs an input of energy to reduce the 3pg molecules that resulted from the first stage. where does this energy input come from?
ATP and NADPH that were supplied through the light reactions
Explanation;
Calvin cycle reaction is the portion of photosynthesis that takes place in the stroma of chloroplasts and can occur in the dark; it uses the products of the light reactions to reduce CO2 to a carbohydrate.
The Calvin cycle is divided into three portions: CO2 fixation, CO2 reduction, and regeneration of RuBP. Because five G3P are needed to re-form three RuBP, it takes three turns of the cycle to have a net gain of one G3P. Two G3P molecules are needed to form glucose.