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Photosynthesis is responsible for creating NADPH and ATP and the Calvin-Benson-Bassham cycle (CBB) uses those high energy molecules to drive the production of glyceraldehyde-3-phosphate (G-3-P). G-3-P can then be used to synthesize hexose sugars which are the primary source of nutrients for heterotrophs.
Because ATP and NADPH are required for the CBB to proceed it is necessary for photosynthesis to occur prior. Photosynthesis (a light dependent reaction) uses light energy to produce ATP and NADPH which can then be used to drive synthesis of of carbohydrate molecules in the CBB, namely glyceraldehyde-3-phosphate. Although the CBB cycle has been given the nick name the "dark reaction" the enzymes involved are activated by light. Light stimulates changes in pH in the different regions of the plant cell which then in turn create a better environment for the CBB enzymes. The enzymes in the CBB cycle are very similar to other enzymes found in other metabolic path ways with the exception that they are found in the stoma instead of in the cytoplasm like in glycolysis.
The diagram directly below is an extremely abbreviated version of the CBB cycle.
This stage is very similar to the isomerization phase of PPP. Enzymes for these reactions are in red
This phase of CBB very closely resembles part of gluconeogenesis. Enzymes for these reactions are in red
This phase of CBB very closely resembles the rearrangement phase of PPP. Enzymes for these reactions are in red
This material is based upon work supported by the National Science Foundation under Grant Number 1246120