Question

how glucagon affect the glycolysis and gluconeogenesis?

is any about enzymes (activation/inactivation)will be included on the whole reaction? if it is reality, they (the substrate) will produce any product?

thanks

Answer 1

Glucagon, a pancreatic hormone is responsible for the increase production of glucose.

Thus it will prevent glycolysis, and promote gluconeogenesis. Glucagon and insulin, act in an antagonistic manner.

They are coordinated in such a way., that while within a cell one pathway is relatively inactive and the other pathway is highly active, and this happens in liver.

Phosphofructokinase ( PFK) and fructose 1,6-bisphosphatase are also oppositely controlled by fructose 2,6-bisphosphate in the liver . Fructose 2,6-bisphosphate stimulates phosphofructokinase and inhibits fructose 1,6-bisphosphatase. Hence,

In the fed state:

We know, the level of fructose 2,6-bisphosphate is high in the fed state .

Glycolysis is accelerated and gluconeogenesis is reduced.

In starvation: Glucagon rises:

1. It stimulates production of two key enzymes : -

a. phosphoenol pyruvate carboxykinase & b. fructose 1,6- bisphosphotase.

Gluconeogenesis predominates because the level of F-2,6-BP decreases.

Glucose formed by the liver under these conditions is essential for the nutrition of brain and muscle.

2. Tthe inhibition of pyruvate kinase by phosphorylation during starvation is another way to prevent glycolysis.