What is the primary function of glucagon?

The primary function of glucagon is to increase blood sugar levels. It is a hormone produced by the alpha cells of the pancreas, and it plays a critical role in maintaining glucose homeostasis. When blood sugar levels drop, glucagon is released into the bloodstream and targets the liver, prompting it to convert stored glycogen into glucose through a process called glycogenolysis. Additionally, glucagon stimulates gluconeogenesis, which is the production of glucose from non-carbohydrate sources. This release of glucose into the bloodstream raises blood sugar levels, providing the necessary energy for the body's cells, particularly during fasting or between meals. In contrast, the other options focus on processes that lower blood sugar, store fat, or synthesize proteins, which are not the primary actions associated with glucagon.