Question

On Glycogen storage disease, Alex has a deficiency in the enzyme muscle phosphorylase a which leads to high levels of glycogen. Explain why Alex has lower levels of lactate compared to a control after a workout? Be sure to mention what is the purpose of producing lactate in a healthy human.

Answer 1

McArdle's Disease is a glycogen storage disease in which there is a deficiency of Phosphorylase enzyme in the muscle.

Skeletal muscle is the store house of glycogen in humans. With healthy individuals, during exercise, the glycogen is phosphorylated by phosphorylase and broken down into glucose, which then undergoes glycolysis resulting in the production of lactic acid from pyruvic acid.

In McArdle disease condition, there is no sufficient production or absence of the enzyme. As a result, during exercise phosphorylation of glycogen is low in these individuals and less level of glycolysis and hence low level of lactate production.

Purpose of Lactate -

It is used in the lipid metabolism resulting in a decrease in the fat level in the body.

It is the Lactate that has been used as a source of energy in the brain to carry out its metabolism.

Production of lactic acid from glucose requires less energy and low oxygen.

It is useful in maintaining the acid-base balance of the body.