1: Gluconeogenesis Flashcards
How much glucose does the body need each day?
160g
How long can direct glucose reserve meet the needs of the body?
One day
Seven possible precursors for gluconeogenesis (with three main ones)
Main ones: lactate, AAs, glycerol
Others: fructose, galactose, glycogen, propionate
Which four enzymes in gluconeogenesis bypass the three irreversible steps of glycolysis?
- Pyruvate carboxylase
- PEP carboxykinase
- F1,6 Bisphosphatase
- Glucose-6-Phosphatase
Which one enzyme of gluconeogenesis is in the mito?
Pyruvate carboxylase
Three things used by pyruvate carboxylase
ATP, CO2, biotin
What substance activates all four major enzymes of gluconeogenesis?
Cortisol
What two things activate pyruvate carboxylase?
Acetyl coA, cortisol
Three things that activate transcription of PEP carboxykinase
Glucagon, thyroxine, cortisol
What is the rate limiting enzyme of gluconeogenesis
F1,6-bisphosphatase
What two things activate and what two things inhibit F1,6bisphosphatase
Activated by: citrate, cortisol
Inhibited by: AMP, F2,6BP
Glucose-6-phosphatase is only found in which four organs?
Liver, kidneys, SI, pancreas
Glucose-6-phosphatase is not in the cytosol, where is it found?
ER lumen
What one thing activates glucose-6-phosphatase?
Cortisol
How does OAA leave mito and enter the cytoplasm? (3 steps)
- Mito malate dehydrogenase: OAA -> malate
- Malate shuttle: transfers to cyto
- Cytosolic malate dehydrogenase: malate -> OAA
