Glycogen metabolism involves the breakdown of glycogen to glucose-6-phosphate through glycogenolysis. Glycogenolysis occurs in three steps: 1) glycogen phosphorylase cleaves glucose from glycogen, 2) transferase and alpha-1,6-glucosidase remodel glycogen to allow further degradation, and 3) phosphoglucomutase converts glucose-1-phosphate to glucose-6-phosphate. In liver, glucose-6-phosphatase converts glucose-6-phosphate to glucose for blood glucose regulation. In muscle, glucose-6-phosphate enters glycolysis for rapid energy production.