Question

BIOCHEM Question

An inherited mutation can lead to the loss of glucose-6-phosphatase activity. Describe how this will affect the functioning of glycolysis and gluconeogenesis, and glycogen storage.

Answer 1

Answer:

An inherited mutation can lead to the loss of glucose-6-phosphatase activity.

It will not affect the functioning of glycolysis because the enzyme, glucose-6-phosphatase has no role in glycolysis.

The function of gluconeogenesis will be disrupted in this condition, because glucose-6-phosphatase is the final enzyme in gluconeogenesis pathway (synthesis of glucose from non-carbohydrate source). Glucose-6-phosphatase catalyzes the reaction of conversion glucose-6-phosphate into glucose and inorganic phosphate which is the final step of gluconeogenesis. Thus, if the activity of glucose-6-phosphatase is lost the gluconeogenesis pathway will not be completed.

It will affect the functioning of glycogen storage in such way that glycogen synthesis (glycogenesis) will occur without any disruption but the breakdown of glycogen (glycogenolysis) will be disrupted. As a result glycogen will be stored but stored glycogen will not be broken down into glucose. Glucose-6-phosphatase catalyzes the reaction of conversion glucose-6-phosphate into glucose in the final step of glycogenolysis. Thus, if the activity of glucose-6-phosphatase is lost the glycogenolysis pathway will not be completed.