C3 photosynthesis
The photosynthetic pathway used by cannabis and most plant species, named for the three-carbon compound formed when carbon dioxide first enters the Calvin cycle.
In C3 photosynthesis, Rubisco RuBisCO The enzyme that begins carbon fixation by adding carbon dioxide to RuBP. It can also react with oxygen, initiating photorespiration. adds carbon dioxide directly to a five-carbon molecule in the Calvin cycle. The unstable six-carbon product immediately splits into two three-carbon molecules, which give the pathway its name.
C3 plants do not first concentrate carbon dioxide around Rubisco as C4 and CAM plants do. Their carbon fixation is therefore more sensitive to carbon dioxide availability and to photorespiration. Cannabis uses the C3 pathway.