Advanced Dental Admission Test (ADAT)

Which of the following processes is NOT triggered by insulin?

1. Glycogen formation

2. Cellular glucose uptake

3. Glycogenolysis

4. Fatty acid synthesis

The correct answer is: Glycogenolysis

Insulin is a key hormone in the regulation of glucose and lipid metabolism. It promotes various anabolic processes that help in storing energy. Among these processes are glycogen formation, cellular glucose uptake, and fatty acid synthesis, all of which are stimulated by insulin. Glycogen formation, also known as glycogenesis, is the process by which excess glucose is converted into glycogen for storage in liver and muscle cells. This is a direct action of insulin, which enhances the activity of glycogen synthase, the enzyme responsible for this transformation. Cellular glucose uptake refers to the process by which glucose is transported into the cells. Insulin facilitates this process by promoting the translocation of glucose transporter proteins (like GLUT4) to the cell membrane, allowing cells to take in glucose more efficiently. Fatty acid synthesis is the metabolic pathway where acetyl-CoA is converted into fatty acids. Insulin not only stimulates this synthesis in adipose tissue and the liver, but it also promotes the production of other critical substrates necessary for this process. However, glycogenolysis, which is the breakdown of glycogen into glucose, is not promoted by insulin. Instead, glycogenolysis is stimulated by hormones such as glucagon and epinephrine, particularly