Triose phosphate (TP) is the 3-carbon product of the Calvin cycle, made when GP is reduced using ATP and reduced NADP. It is the starting point for making all the organic molecules a plant needs.Regenerating RuBP. Most TP is recycled. Of every six molecules of TP made, five are used to regenerate three molecules of RuBP, using ATP. Only one in six leaves the cycle to be used elsewhere.Worked example: fixing 6 molecules of CO2 makes 12 GP and so 12 TP. Ten TP regenerate 6 RuBP, leaving 2 TP (6 carbons), enough for one molecule of glucose.The TP that leaves the cycle is used to make:• Carbohydrates: two TP join to form a hexose sugar such as glucose. Glucose is used in respiration, or joined to form sucrose (for transport in the phloem), starch (for storage) and cellulose (for cell walls).
• Lipids: TP is converted to glycerol, and to acetyl CoA, which is used to make fatty acids. These combine to form triglycerides and phospholipids.
• Amino acids: TP is converted to other organic compounds that are combined with nitrogen (absorbed as nitrate ions) to form amino acids, which are used to make proteins.
• Nucleic acids: the pentose sugars in DNA and RNA are also made from TP.So the Calvin cycle is not just a source of glucose: TP is the raw material for almost all the biological molecules in the plant.
• Lipids: TP is converted to glycerol, and to acetyl CoA, which is used to make fatty acids. These combine to form triglycerides and phospholipids.
• Amino acids: TP is converted to other organic compounds that are combined with nitrogen (absorbed as nitrate ions) to form amino acids, which are used to make proteins.
• Nucleic acids: the pentose sugars in DNA and RNA are also made from TP.So the Calvin cycle is not just a source of glucose: TP is the raw material for almost all the biological molecules in the plant.