What is the relationship between insulin and blood glucose?

• A. Insulin raises glucose by stimulating glucose production in the liver.
• B. Insulin promotes uptake of glucose into cells, lowering blood glucose.
• C. Insulin has no effect on glucose levels.
• D. Insulin only affects lipid metabolism.

Answer: (B)

Insulin lowers blood glucose by promoting uptake of glucose into cells and by reducing glucose production in the liver. After a meal, the pancreas releases insulin, which signals muscle and fat cells to bring glucose into the cells by increasing GLUT4 transporters on the cell surface. This uptake pulls glucose out of the bloodstream, lowering blood glucose levels. In the liver, insulin suppresses glucose production and supports glycogen synthesis, further helping to decrease circulating glucose. The other statements don’t fit because insulin does not raise glucose, it does have a clear effect on glucose regulation, and its actions include more than just lipid metabolism.