Insulin is a protein hormone whose function is to
- A. raise blood glucose concentration
- B. lower blood glucose concentration by promoting uptake and storage
- C. digest proteins in the stomach
- D. carry oxygen
Explanation
Secreted by the beta cells of the pancreas, insulin increases the permeability of cells to glucose and stimulates its conversion into glycogen, so blood glucose falls. Glucagon raises it, and the two form a negative feedback pair. Insulin was the first protein to have its full amino acid sequence determined.