Lecture 16 - Gluconeogenesis Flashcards
Whole body needs […] glucose per day.
160 g
Daily glucose requirement of brain.
120 g
Glucose present in body fluids.
20 g
Glucose readily available from glycogen is […].
190 g
Location of gluconeogenesis.
Liver and kidney
Gluconeogenesis converts […] to […].
Pyruvate; Glucose
Major precursors of gluconeogenesis.
Lactate, amino acids, and glycerol
Enzyme of gluconeogenesis, converts pyruvate to oxaloacetate (OAA).
Pyruvate carboxylase
Location of pyruvate carboxylase.
Mitochondria (i.e. significance = All other enzymes in the cytoplasm)
Method by which OAA is transported to cytoplasm.
Malate shuffle
Enzyme of gluconeogenesis, converts GAP + DHAP to fructose 1,6-bisphosphate.
Fructose 1,6-bisphosphatase
Rate limiting enzyme of gluconeogenesis.
Fructose 1,6-bisphosphate
Enzyme of gluconeogenesis, converts Glucose 6-phosphate to glucose.
Glucose 6-phosphatase
Location of glucose 6-phosphatase.
Endoplasmic reticulum
Protein, transports glucose 6-phosphate to ER.
T1
Protein, transports inorganic phosphate back into cytosol.
T2
Protein, transports glucose back to cytoplasm.
T3
Four enzymes of gluconeogenesis, not found in glycolysis, by-pass the irreversible steps of glycolysis.
Pyruvate carboxylase, phosphoenolpyrubate carboxykinse, fructose 1,6-bisphosphate, and glucose 6-phosphate
3 enzymes of gluconeogenesis that utilize ATP/GTP.
Pyruvate carboxylase, phosphoenolpyruvate carboxykinase, phosphoglycerate kinase.
[…] determines which pathway will be most active (i.e. gluconeogenesis or glycolysis).
Energy charge (i.e. ATP/ADP ratio)
Gluconeogenesis and glycolysis are […] regulated.
Reciprocally
Glycolysis is favored when blood […] is high.
Insulin
Gluconeogenesis is favored when blood […] levels are low and glycogen stores are depleted.
Gluconeogenesis
Tissue location of gluconeogenesis.
Liver, kidneys, small intestine
Positive regulators of glycolysis.
Glucose, insulin, AMP, Fructose 2,6-Bisphosphate, Fructose 1,6-Bisphosphate
Positive regulators of gluconeogenesis.
Glucagon, citrate, cortisol, thyroxine, acetyl CoA
Negative regulators of glycolysis.
Glucagon, ATP, citrate, Glucose 6-Phosphate, Fructose 6-Phosphate, alanine
Negative regualtors of gluconeogenesis.
ADP, ANP, Fructose 2,6-Bisphosphate
Enzyme, converts fructose 6-phosphate to fructose 2,6-bisphosphate which stimulates PFK.
Phosphofructokinase 2
Bi-functional enzyme, stimulated/inhibited via concentration of fructose 2,6-bisphosphate allowing for the control of glycolysis.
Phosphofructokinase 2 and fructose bisphosphate 2
Hormonal control of phosphofructokinase 2 and fructose bisphosphatase 2.
Insulin and glucagon
Process, lactate produced in skeletal muscle/RBCs is converted back to pyruvate in the liver (i.e. pyruvate can enter gluconeogenic pathway and regenerate glucose)
Cori cycle
