How does the adrenaline hormone cause the conversion of glycogen to glucose?

This can best be described as the second messenger model. Adrenaline is a hydrophillic hormone so it only acts on receptors on the cell surface membranes. The hormone fuses to the receptor site which then activates the release of an enzyme called adenyl cyclase. This enzyme helps convert ATP to cyclic AMP (cAMP).cAMP behaves as the second messenger. An increase in cAMP levels activates specific enzymes called protein kinases which then phosphorylate and active other key enzymes, such as digestive enzymes. These all work together to convert (break down) glycogen to glucose.The second messenger model is a model regularly seen throughout human biology in various processes, mostly including the use of hydrophillic hormones.