Lecture 14 - Regulation of gluconeogenesis

Question 1

How does glucagon regulate gluconeogenesis

Answer 1

downregulates the expression of glycolytic enzymes and upregulates the expression of gluconeogenic enzymes, such as glucose-6-phosphatase and PEPCK

Glucagon also stimulates glycogenolysis

Question 2

How does allosteric regulation affect gluconeogenesis

Answer 2

Allosteric regulation of fructose 1,6-bisphosphatase

Regulated by metabolites such as fructose 2,6-bisphosphate, which allosterically inhibits fructose 1,6-bisphosphatase (but activates phosphofructokinase-I

Question 3

How is pyruvate carboxylase allosterically regulated during gluconeogenesis

Answer 3

Pyruvate carboxylase is allosterically regulated by acetyl CoA

Question 4

What is gluconeogenesis regulated by

Answer 4

Blood glucose levels  hormones (insulin and glucagon)

Downstream glycolytic metabolites

Energy status of cell (ATP : AMP ratio)

AMP and ADP inactivate gluconeogenic enzymes

Downstream glycolytic metabolites (such as citrate and acetyl coA) activate gluconeogenic enzymes