Gluconeogenesis Flashcards
Proceeds via the synthesis of what in the mitochondria?
Gluconeogenesis preoceeds via the synthesis of oxaloacetate in the mitochondira
What is the importance of oxaloacetate? What does it accept?
Accepts acetyl groups from fat breakdown
(oxaloacetate is an intermediate in the TCA cycle)
Can be synthesised fro pyruvate
Precursors for gluconeogenesis?
Lactate
Amino acids
Glycerol
Where does gluconeogenesis take place?
In the liver
small amounts in the kidneys
Where does the energy for gluconeogenesis come from?
The oxidation of fatty acids in fat tissue
How many pyruvate molecules needed to make 1 glucose molecule?
2
What happens to lactic acid in the liver?
It is converted into lactate and then to pyruvate and back to glucose (released into bloodstream)
(this costs 6ATP)
Removing the lactic acid means that the liver/blood won’t become too acidic
Ketogenic amino acids
Cannot be used for making glucose
Glucogenic amino acids
Can serve as precursors for gluconeogenesis
The Cori cylce
Lactate and muscle and blood and liver etc
How do amino acids enter TCA cycle?
At one of the stages
Oxaloacetate
Or converted to pyruvate which can then be converted into oxaloacetate
What are ketogenic amino acids converted into?
Acetyl CoA or acetoacetyl coA
They can then enter the TCA cycle but ONLY if oxaloacetate is already present
What accepts acetyl groups in the TCA cycle?
Oxaloacetate
Hormonal regulation of gluconeogenesis
Glucagon (stimulates)
Insulin (inhibits)
Fructose 2,6-biphosphate is high/low in which state?
High in fed state, low in starved state
Intermediate of glycolysis
-Stimulates glycolysis at high concentrations and inhibits gluconeogenesis
