Question

Deficiency of____ enzyme is found in Hers’ disease.

• A. Muscle glycogen phosphorylase
• B. Liver glycogen phisphorylase
• C. Phosphofructokinase
• D. Glucose-6-phosphatase

Answer 1

The Correct Option is B

Hers' disease, also known as Glycogen Storage Disease Type VI, is a metabolic disorder characterized by the deficiency of a specific enzyme. In this disease, there is an accumulation of glycogen in the liver due to its incomplete breakdown.

The enzyme that is deficient in Hers' disease is Liver glycogen phosphorylase. This enzyme is responsible for catalyzing the phosphorolysis of glycogen to produce glucose-1-phosphate, which can then be converted into glucose-6-phosphate and enter the glycolytic pathway to provide energy.

Let's examine each option to confirm why the correct answer is Liver glycogen phosphorylase:

• Muscle glycogen phosphorylase: This enzyme is involved in the degradation of glycogen in muscle tissues, not in the liver. Therefore, its deficiency does not cause Hers' disease.
• Liver glycogen phosphorylase: As mentioned, this enzyme is vital in breaking down glycogen in the liver. A deficiency in this enzyme stops the normal breakdown of glycogen, leading to its excessive accumulation in the liver, thus causing Hers' disease.
• Phosphofructokinase: This enzyme plays a role in glycolysis, converting fructose-6-phosphate into fructose-1,6-bisphosphate. It is not directly related to glycogen breakdown and is unrelated to Hers' disease.
• Glucose-6-phosphatase: Its deficiency results in Von Gierke's disease (Glycogen Storage Disease Type I), which is characterized by the inability to convert glucose-6-phosphate into free glucose, leading to a different type of glycogen storage disease.

Thus, the correct answer is Liver glycogen phosphorylase because it specifically addresses the enzymatic deficiency leading to Hers' disease.