What is the primary function of Glucagon?

The primary function of glucagon is to increase blood sugar levels, particularly by promoting gluconeogenesis and glycogenolysis in the liver. When blood glucose levels are low, glucagon is released to signal the liver to convert stored glycogen back into glucose, thereby raising blood sugar levels.

The role of glucagon involves the mobilization of energy stores rather than acting as a direct energy source or promoting glycogen storage. It does not convert amino acids into glucose as its primary function; that process is primarily associated with gluconeogenesis but not directly driven by glucagon. In the context of the question, while glucagon can influence the conversion of amino acids into glucose during gluconeogenesis, its essential role centers around regulating blood glucose levels, specifically under fasting conditions.