Biochemistry Podcast - Gluconeogenesis Flashcards
What is gluconeogenesis
synthesis of glucose within the body from non-carb precursors
during prolonged starvation - new glucose has to be synthesised
What are the precursors used?
Lactate
Amino acids
Glycerol
How is lactate used in gluconeogensis?
Lactate - synthesised by skeletal muscle under anaerobic conditions
How is Amino acids used in gluconeogensis?
Amino acids - derived from muscle protein by proteolysis
How is glycerol used in gluconeogenesis?
Glycerol - derived from triglycerides by lipolysis in adipose tissue
is gluconogenesis energy using?
YEs - the energy comes from oxidation of stored molecules, fatty acids released from adipose tissue as well as body protein
Where does gluconeogensis occur?
In the liver, tiny amounts in the kidney
What are the 3 irreversible reactions in glycolysis?
Hexokinase
Phophofructokinase
Pyruvate kinase
What is gluconeogensis almost the reverse of?
Glycolysis
Does gluconeogensis use a lot or little energy?
LOTS - requires 6 ATP
How much ATP does gluconeogensis need to occur?
6 ATP
How is lactate formed?
Formed from pyruvate in anaerobic conditions, it is then transported to the liver in the bloodstream and liver converts the lactate back to glucose and can then realise it into the blood stream.
What does the liver do with the lactate from the muscles?
It converts it back to glucose and releases it into the bloodstream
Which class of amino acid can be use for precursors of gluconeogenesis?
glucogenic not ketogenic
How are glycolysis and gluconeogenesis regulated?
By hormone regulation - glucagon (stimulate gluconeogenesis, inhibit glycolysis)
Insulin - inhibits gluconeogenesis
By individual cell levels - allosteric effectors (AMP or ADP, high ATP…. etc)
