Final answer:
Glucagon stimulates the liver to convert glycogen into glucose and convert amino acids into glucose, increasing blood glucose levels.
Step-by-step explanation:
When blood glucose levels decline below normal levels, the hormone glucagon is released from the pancreas. Glucagon stimulates the liver to convert glycogen back into glucose in a process called glycogenolysis. Glucose is then released into the bloodstream for energy by the muscle cells and liver cells. In addition, glucagon stimulates the liver to convert amino acids into glucose through a process called gluconeogenesis. These actions of glucagon result in an increase in blood glucose levels to maintain homeostasis.