1 Describe the regulation of glycogen metabolism 2 How would

1) Describe the regulation of glycogen metabolism.

2) How would a riboflavin deficiency affect the functioning of the citric acid cycle? Why?

Solution

1).

The “Islets of Pancreas” constitute the endocrine cells of the pancreas (islets of Langerhans) contain four types of cells namely “alpha, beta, delta and F cells.” Alpha cells secrete glucagon and beta cells secrete insulin. Delta cells produce somatostatin, and F cells produce pancreatic polypeptide (PP) hormone.

The secretion of insulin and glucagon is regulated by a negative feedback mechanism. Glycogen is the storage form of excessive glucose. During the fed state, the blood glucose levels are high, which triggers the release of insulin. Insulin converts glucose into glycogen. When the blood glucose levels decrease, the insulin levels decrease and glucagon is released to break down the glycogen and release glucose into the circulation.