Gluconeogenesis Flashcards
What three enzymes are unique to gluconeogenesis
Pyruvate carboxylase
PEP carboxykinase
Fructose 1 6 biphosphatase
Glucose 6 phosphatase
Pyruvate carboxylase
Enzymes, pyruvate to OAA, requires biotin and 2ATP
Biotin
Cofactor in pyruvate carboxylase. Amide linkage to lysine.
PEP carboxylase
OAA to phosphoenol pyruvate. Requires 2GTP, loses CO2
Fructose 1 6 biphosphatase
Fructose 1 6 biphosphate to fructose 6 phosphate. Requires H2O loses P
Glucose 6 phosphatase
Glucose 6 phosphate to glucose. Requires H2O loses P. Some people lack this-hypoglycemic.
What are other precursors that can jump into gluconeogenesis
Lactate to pyruvate
Amino acids to OAA
How does OAA get out of the mitochondria
Converted to malate and then reconverted in cytosol, this also restores NADH
Which gluconeogenesis precursor path is predominant
Lactate because it generates NADH so malate export is not needed, OAA turns directly into PEP
Do glycolysis and gluconeogenesis run simultaneously
No, that’s why it has different enzymes
Which is more costly
Gluconeogenesis uses 6 energy bonds, glycolysis gains 2
What is the cost in ATP going through glycolysis and then gluconeogenesis
4 ATP
How can glycolysis and gluconeogenesis be irreversible
Large and negative free energy changes
Which three enzymes in glycolysis is not used in gluconeogenesis
Hexokinase
Phosphofructokinase
Pyruvate kinase
