Photosynthesis

The light indepedent reactions make up the second and final phase of photosynthesis.  They occur in the stroma, the substance surrounding the thylakoids within the chloroplasts.  The focus of the light independent reactions is to perform carbon fixation, which is the process of converting inorganic molecules into organic molecules.  In photosynthesis, this means attaching CO2 to a chain of carbon atoms to produce a molecule of glucose.  There are three different pathways of fixing carbon, called C3, C4, and CAM.  

 

CO2 is a reactant of each varying pathway.  The products of this reaction are oxygen, which diffuses out of the plant, and glucose, which the plant uses to store energy.  The light independent reactions can be thought of as a packing plant in a factory.  The workers, which are an enzyme called RuBisCo, takes CO2 and a carbon chain and packs them together.  The final result of all of this packing, after six rounds of what is called the Calvin Cycle, is a molecule of glucose.