Where does gluconeogenesis occur?
Primarily in the liver but also in the renal cortex and the epithelial cells in the small intestine
What are the most common precursors of glucose? (hint 4 total)
Lactate
Pyruvate
Glycerol
Amino acids
What is the gori cycle?
Lactate produced during anaerobic glycolysis in skeletal muscle is transported to liver and converted to glucose which can then move back to the muscle and be converted to glycogen
How many steps do gluconeogenesis and glycolysis share?
7
What 3 reactions in glycolysis are irreversible?
Step 1 (Glucose -> glucose 6-phosphate)
Step 3 (Fructose 6-phosphate -> fructose 1,6-biphosphate)
Step 10 (Phosphoenolpyruvate -> pyruvate)
How is pyruvate converted to phosphoenolpyruvate in first step of gluconeogenesis?
Pyruvate is converted to oxaloacetate and then further reduced to malate in mitochondria. Afterwards it can be oxidized to oxaloacetate and converted to phosphoenolpyruvate in cytosol
How is lactate converted to phosphoenolpyruvate in first step of gluconeogenesis?
Converted to pyruvate in cytosol which is then converted to oxaloacetate and then phosphoenolpyruvate.
How is fructose 6-phosphate generated from fructose 1,6-biphosphate?
By hydrolysing C-1 phosphate which is done by FBPase-1
How is glucose 6-phosphate converted to glucose?
hydrolysing the phosphate ester which is done by glucose 6-phosphatase.
Can acetyl-CoA be converted to pyruvate?
No, no such pathway exists in mammals.
Can glycerol participate in the gluconeogenesis?
Yes if it is phosphorylated by glycerol kinase and then oxidized at central carbon it becomes dihydroxyacetone phosphate.
How can alanine be converted to pyruvate?
By transamination.
What enzyme catalyses conversion from pyruvate to oxaloacetate?
pyruvate carboxylase with coenzyme biotin.
