What is the role of insulin in glucose regulation?

• A. It converts glucose to glycogen for storage
• B. It helps cells take up glucose from the blood, lowering blood sugar
• C. It raises blood sugar by releasing glucose from the liver
• D. It decreases insulin production

Answer: (B)

Insulin's job is to move glucose from the bloodstream into body cells, which lowers blood sugar. After you eat, blood glucose rises and the pancreas releases insulin. Insulin binds to receptors on muscle and fat cells and triggers GLUT4 transporters to the cell surface, letting glucose enter the cells. In the liver, insulin promotes turning excess glucose into glycogen for storage and also suppresses the liver’s production of new glucose, helping blood sugar fall toward normal levels. It doesn’t raise blood sugar by releasing liver glucose, and it doesn’t decrease its own production when blood sugar is high. So the best description is that insulin helps cells take up glucose from the blood, lowering blood sugar.