Question

In terms of blood glucose homeostasis, compare the roles of liver glycogen and muscle glycogen in the body?

a. Liver glycogen is the first and immediate source of glucose for the maintenance of blood glucose levels. Glucose 6-Phosphate only located in liver and kidney . In muscle, glycogen used to generate ATP
b. Glycogenin is a protein that helps in the synthesis of new glycogen primer molecules.
c. The protein to which glycogen is attached, glycosylates itself
d. then extends the carbohydrate chain until the glucosyl chain is long enough to serve as a substrate for glycogen synthase.

Answer 1

Liver glycogen is crucial for maintaining blood glucose levels and supplies glucose to the body, whereas muscle glycogen is used solely for muscle energy needs during exercise and does not directly contribute to blood glucose levels.

Step-by-step explanation:

Liver glycogen serves as a regulator of blood glucose homeostasis, providing glucose to other cells and maintaining blood glucose levels within the normal range. It is capable of glycogenolysis, the breakdown of glycogen into glucose, which is then released into the bloodstream for use by the body. On the other hand, muscle glycogen is a localized energy reserve that is primarily used to produce ATP during vigorous exercise, directly benefiting the muscle itself through glycolysis. Unlike liver glycogen, muscle glycogen does not contribute directly to the maintenance of blood glucose levels, as it lacks glucose 6-phosphatase, the enzyme needed to convert glucose 6-phosphate back to glucose.

Glycogen metabolism is essential for balancing energy supply during fasting, exercise, or between meals. The liver acts as a central hub for managing these energy reserves and providing systemic glucose via gluconeogenesis, while muscles store glycogen for their specific energy needs during physical exertion.