The Normal Pathways How Glycogen Made and Broke Down - Essay Example

Glycogen synthesis which is also known as glycogenesis involves the addition of glucose molecules onto glycogen for the storage purposes. The process takes place in the liver, from where the activation is done by insulin, the hormone responsible for lowering blood sugar levels, in instances of high glucose levels. The process is a two-step process involving various enzymes that play significant roles in catalyzing the process. The first step in glycogen synthesis is the process involving phosphorylation of glucose to form glucose-6-phosphate (G6P).

The process is a phosphorylation process and is acted upon by an enzyme named hexokinase or glucokinase. This involves the addition of a phosphate molecule onto the glucose on the sixth carbon atom resulting into the formation of Glucose-6-Phospahete (Hers, 1970). From the action of Phosphoglucomutase enzyme on Glucose-6-Phospahte, an intermediary of glucose-1, 6-bisphosphate is formed, but this is usually temporary, after which it is later converted to glucose-1-phosphate. The phosphoglucomutase enzyme involved in the above reaction, acts to transfer the phosphate group to and from the alpha 1 carbon to the alpha 6 carbon glucose molecule respectively.

The formed glucose-1-phosphate then undergoes certain chain of intermediate reactions that change it to Uridyl Diphosphate-glucose complex (UDP-glucose complex). This happens in the presence of Uridyl Triphosphate, in which one molecule of phosphate is released to form pyrophosphate. The process resulting into the formation of the UDP-glucose complex usually occurs as a result of the action of Uridyl Transferase which in certain cases is called UDP-glucose pyrophosphorylase. At this point, through the activation by insulin, glycogen synthase gets grip of the glucose molecule from the complex and attaches it to glycogen, the form in which it is stored (Halse, 2000).

In the glycogen synthase catalyzed reaction, the carbon number 1 of Uridyl Diphosphate-glucose complex attaches to the carbon number 4 of the non-reducing end of the glycogen chain, from where the glucose molecule from the Uridyl Diphosphate-glucose complex to attach it to the glycogen chain. This process is considered to be genetically stable as during the reaction, the Uridyl triphosphate is converted to Uridyl Diphosphate, thereby releasing energy in the form of UTP (Hers, 1970). The whole process is considered reversible as in instances, in which the body’s glucose levels go down, the body is able to initiate the breakdown of glycogen molecules to form glucose through the process of glycogen metabolism.

Glycogen metabolism and synthesis are considered to be regulatory processes in the body for creation of a balance in the body’s blood glucose levels (Newgard, 1989). After intake of meals heavy in glucose, the blood glucose levels rise, a stimulating factor to glycogen synthesis in the liver. This would then result into the conversion of the glucose molecules to glycogen molecules which are then stored for future use. The reverse is also true in instances in which blood glucose levels go down.

The body is again able to activate the breakdown of glycogen to form glucose. Regulation and control of glycogen synthesis is an almost similar to the aspects discussed above, only that in this perspective, in-depth analysis is established. Three hormones play a substantive role in ensuring that control and balances are