BIOCHEM 2EE3 Lecture Notes - Lecture 10: De Novo Synthesis, Phosphoenolpyruvate Carboxykinase, Pentose Phosphate Pathway
17 Sep 2016
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Document Summary
Carbohydrate metabolism gluconeogenesis and pentose phosphate pathway. Gluconeogenesis is the de novo synthesis of glucose that occurs when the body"s stores of glycogen ae low. Occurs primarily in liver, with some gluconeogenesis occurring in kidney. Precursors (amino acids, tca cycle intermediates, and pyruvate) can be converted into oxaloacetate (which is then converted to glucose via. gluconeogenesis) Large changes in free energy in glycolysis. More atp is needed than it is produced by glycolysis, thus it is costly to produce glucose from scratch. Glucose is then exported from the liver when depleted levels occur. Flux through gluconeogenesis is regulated reciprocally to flux through glycolysis to avoid futile cycling. A key point in the regulation of gluconeogenesis occurs at fructose bisphosphatase: fructose bisphosphate is inhibited by high concentrations of amp, and fructose- When the energy state of the cell is high (high levels of atp, low of amp/adp) gluconeogenesis is stimulated.
