Question

Describe how glucose-6-phosphate formed by glycogen breakdown in the liver converts to glucose by glucose-6-phosphatase and how the newly formed glucose leaves the liver cells. Describe why this process allows for separation from glycolysis.

Answer 1

Poly and di monosaccharides are converted to mono in intestine, taken up and transported to the liver.glycogen is degraded into monosaccharides.
Glucose 1-phosphate by glycogen phosphorylase and Pi,ATP is not used for this reaction.Glucose 1-P is transformed into glucose 6-p by enzyme Phosphoglucomutase and Enters the glycolysis.Phosphorylated carbohydrates cannot pass the membranes.The carbohydrates are hydrolyzed rather than phosphorylyzed in the intestine before being transported into the cells and further into the blood stream .Dietary glycogen is hydrolyzed by amylase to glucose .

The reaction of the glycolysis:
Glucose + 2 ADP + 2 Pi + NAD+ ? 2 Pyruvate + 2 ATP + 2 NADH + 2 H+ 2 H2O
this reaction Produces 2 high energy phosphate groups and 2 NADH

The reaction of the Gluconeogenesis:
2 Pyruvate + 4 ATP + 2 GTP + 2 NADH + 2 H+ + 4 H2O ? Glucose + 4 ADP + 2 GDP + 6 Pi + 2 NAD+

this reaction Costs 6 high energy phosphate groups and 2 NADH