Second stage of photosynthesis – Calvin Cycle

The carbon fixation stage (Calvin Cycle) is a series of enzyme controlled reactions which does not require light.

Carbon dioxide enters the cycle and becomes attached to RuBP (ribulose bisphophate) by the enzyme RuBisCO to produce 3-phosphoglycerate (3PG).

The 3-phosphoglycerate that is produced is phosphorylated by ATP and combined with hydrogen from NADPH to form G3P (glyceraldehyde-3-phosphate). G3P is used to either regenerate RuBP or can be used to synthesise sugars, for example glucose.

The Calvin Cycle is the temperature-dependent part of photosynthesis.

The Calvin Cycle

The glucose produced through photosynthesis can also passed into other biosynthetic pathways to form DNA.