Editing Glycogenolysis (section)

==Function==
Glycogenolysis takes place in the cells of the [[muscle]] and [[liver]] tissues in response to hormonal and neural signals. In particular, glycogenolysis plays an important role in the [[fight-or-flight response]] and the regulation of glucose levels in the blood.

In [[myocyte]]s (muscle cells), glycogen degradation serves to provide an immediate source of glucose-6-phosphate for [[glycolysis]], to provide energy for muscle contraction. Glucose-6-phosphate can not pass through the cell membrane, and is therefore used solely by the myocytes that produce it.

In [[hepatocyte]]s (liver cells), the main purpose of the breakdown of glycogen is for the release of glucose into the bloodstream for uptake by other cells. The phosphate group of glucose-6-phosphate is removed by the enzyme [[glucose-6-phosphatase]], which is not present in myocytes, and the free glucose exits the cell via [[GLUT2]] facilitated diffusion channels in the hepatocyte cell membrane.