The cleavage of glycogen by glycogen phosphorylase releases glucose-1-phosphate.
Explanation: Glycogen phosphorylase is an enzyme crucial for glycogenolysis, the process of breaking down glycogen stored in the liver and muscle tissues into glucose. When glycogen is cleaved by this enzyme, it removes glucose units from the non-reducing ends of the glycogen molecule in the form of glucose-1-phosphate. This form of phosphate glucose can then be converted into glucose-6-phosphate, which is an essential molecule for energy production through glycolysis or can participate in maintaining blood glucose levels through gluconeogenesis.