What is glucagon?

• A. A mobilization hormone released by pancreas to increase blood sugar
• B. A storage hormone released by pancreas to decrease blood sugar
• C. Produced by liver
• D. A neurotransmitter

Answer: (A)

Glucagon is a hormone whose job is to raise blood glucose when it drops. It’s released by the alpha cells of the pancreas and signals the liver to mobilize glucose stores—breaking down glycogen and producing new glucose through gluconeogenesis—so glucose flows back into the bloodstream. It’s not produced by the liver, it isn’t a storage hormone (that role belongs to insulin promoting storage as glycogen), and it isn’t a neurotransmitter (it acts through the bloodstream, not at synapses). So describing it as a mobilization hormone released by the pancreas to increase blood sugar is the accurate, best match.