Gluconeogenesis Flashcards
What is gluconegenesis and why does it occur
/formation of new glucose molecules from non carbohydrate molecules ( lactic acid , proteins or phospholipids )
1 hypoglycemia
2 glucose Is 1• source of energy for brain
What is fuel source for brain if glucose low and its dangers
Where does gluconeogenesis occur
- ketone bodies
- causes blood to be acidic ( ketoacidosis )
/liver and kidney ( mainly proximal convulated tubule )
Which three glycolysis steps are irreversible
1 glucose to G6P
2 F6P to F-1,6-P
3 PEP to pyruvate
How is lactic acid converted to glucose
-1st converted into pyruvate
-pyruvate directly into oxaloacetate ( pyruvate carboxylase )
-OAA changed into malate and pushed into cytosol out of mito
-Malate to OAA
-OAA to PEP ( phosphoenol pyruvate carboxykinase )
/PEP all the way to F-1,6-BP
-F-1,6-BP to F6P ( fructose 1,6 bisphosphatase ) phosphate removed at 1
-F6P to G6P
-G6P into SER and into glucose ( glucose 6 phosphatase )
How does G6P enter and leave SER
Net effect after glucose released from cell
- ensure T1 protein
- leave T2 protein
/increased blood glucose levels
Why is OAA converted into Malate in mito
/OAA can’t pass through Mito membrane but Malate can
Describe how TAG converted into glucose
-TAG broken into glycerol and FA ( lipolysis )
-glycerol to glycerol 3 phosphate ( glycerol kinase )
-G3P into DHAP to F 1,6 BP
/the rest
What can happen to fatty acids during gluconeogenesis and the exception
- FA converted Into acetyl CoA ( beta oxidation )
- odd chain FA converted into succinly CoA - Malate - pushed into cytosol ( the rest )
Hormones involved in gluconeogenesis
1 glucagon ( pancreas alpha cells )
2 cortisol
3 thyroid
4 growth hormone
Describe how proteins are converted into glucose
- protein catabolized into aas
- aas react with ketoacids ( alpha ketoglycerate )
- aas becomes ketoacid and is converted into pyruvate or can join krebbs cyber at a certain point depending on aas
- ketoacid now a new aas
