In the insulin sequence, what is the fifth event describing the final step?

In the insulin sequence, what is the fifth event describing the final step?

• A. Glucose enters the bloodstream
• B. Beta cells release insulin
• C. Glycogen converted to glucose by alpha cells
• D. Insulin transports glucose to muscle cells

Answer: (C)

The key idea is that insulin’s final action is to move glucose from the bloodstream into tissues that use or store it. After beta cells release insulin in response to high blood glucose, insulin promotes the uptake of glucose into muscle and adipose cells by causing GLUT4 transporters to come to the cell surface. This is the step that directly reduces circulating glucose and completes the insulin sequence. The option about glycogen being converted to glucose by alpha cells belongs to the glucagon pathway, not insulin; alpha cells secrete glucagon to raise blood glucose by promoting glycogen breakdown in the liver, which is the opposite of insulin’s effect. So the final step in the insulin sequence is the transport of glucose into muscle cells.

The key idea is that insulin’s final action is to move glucose from the bloodstream into tissues that use or store it. After beta cells release insulin in response to high blood glucose, insulin promotes the uptake of glucose into muscle and adipose cells by causing GLUT4 transporters to come to the cell surface. This is the step that directly reduces circulating glucose and completes the insulin sequence. The option about glycogen being converted to glucose by alpha cells belongs to the glucagon pathway, not insulin; alpha cells secrete glucagon to raise blood glucose by promoting glycogen breakdown in the liver, which is the opposite of insulin’s effect. So the final step in the insulin sequence is the transport of glucose into muscle cells.