Gluconeogenesis

A pathway for making glucose from noncarbohydrate sources

• to convert lactic acid made in muscle and other cells back into glucose (liver does 90% of this
• conversion, kidney 10%)
• to make glucose for brain when carbohydrates are not readily available, eg. when diet is low in carbohydrate (brain uses glucose as main energy
• source)
• to make glucose and other sugars for glycoproteins

• 90% in the liver
• 10% in the kidney

• These enzymes are unique because they overcome 3 glycolytic reactions and have strong negative delta G values
• Pyruvate carboxylase/PEP carboxykinase = these two combined convert pyruvate to PEP through and OAA intermediate
• Fructose-1,6-bisphosphate = reverses PFK
• Glucose-6-phosphate = reverses hexokinase

Biotin is used as a cofactor to aid in the transfer of CO2 groups to target various molecules.