Earl Sutherland won the Nobel prize for discovering how epinephrine stimulates the breakdown of glycogen, a molecule that belongs to the carbohydrate family of macromolecules. Glycogen is abundant in liver and in muscle cells and is stored in glycogen granules. When epinephrine interacts with the liver cells it triggers a signal transduction cascade that leads to activation of glycogen phosphorylase and production of glucose-1-phosphate molecules. The glucose-1-phosphate molecules are then used for glycolysis to produce energy in the liver cell. To decipher the signal transduction pathway that triggers the breakdown of glycogen Sutherland and his colleagues used a test tube, the enzyme glycogen phosphorylase, epinephrine and glycogen. In this experiment he observed that no glucose-1-phosphate was formed. Why do you think this happened?