In a plant cell there are many chloroplasts where photosynthesis occurs. Photosynthesis is broken up into two main steps: the light-dependent reactions and the light-independent reactions (sometimes called the dark reactions). The light reactions occur within the thylakoid membranes of the chloroplasts and produce oxygen that is released as a byproduct of splitting water and also the ATP and NADPH that are required for the light-independent reactions.
The light-independent reactions of photosynthesis occur in the ...
In a plant cell there are many chloroplasts where photosynthesis occurs. Photosynthesis is broken up into two main steps: the light-dependent reactions and the light-independent reactions (sometimes called the dark reactions). The light reactions occur within the thylakoid membranes of the chloroplasts and produce oxygen that is released as a byproduct of splitting water and also the ATP and NADPH that are required for the light-independent reactions.
The light-independent reactions of photosynthesis occur in the stroma of the chloroplasts. The NADPH and ATP made during the light reactions along with carbon dioxide from the atmosphere enter a cycle known as the Calvin cycle. The first step of the Calvin cycle combines RuBP (an organic intermediate within the cycle) with the carbon dioxide to create 3-PGA. The enzyme that catalyzes this reaction is RuBisCO and it is the most abundant enzyme on this planet! The conversion of the 6 3-PGA molecules to 6 GA3P molecules utilizes 6 ATP and 6 NADPH. Two molecules of GA3P can come together to produce 1 glucose molecule. It takes two rounds of the cycle to produce 1 glucose. The 5 remaining GA3P go on to produce 3 molecules of RuBP, consuming 3 ATP.