Which of the Following Proteins is a Hormone

Question

Which of the following proteins is a hormone?
A) casein
B) hemoglobin
C) insulin
D) all of these

Accepted Answer

Insulin is a hormone that regulates blood glucose levels. Casein is a protein found in milk, and hemoglobin is a protein found in red blood cells that transports oxygen. While both casein and hemoglobin have important functions in the body, they are not considered hormones.