Module 7 - Glygogenesis Notes

Glycogen

The storage form of glucose in various organisms, serving as a reservoir of glucose units for glycolysis and ATP production.

Alpha1-4 glycosidic bonds

The type of linkages primarily connecting glucose units in glycogen.

Alpha1-6 glycosidic linkages

Branching linkages occurring in glycogen, present roughly every 8 to 10 glucose residues.

Glycogen phosphorylase

An enzyme that catalyzes the breakdown of glycogen by cleaving alpha1-4 glycosidic linkages, releasing glucose 1-phosphate.

Debranching enzyme

An enzyme that removes the alpha1-6 linkages in glycogen, allowing glycogen phosphorylase to continue its action.

Phosphoglucomutase

An enzyme that converts glucose 1-phosphate to glucose 6-phosphate, which has different fates depending on the tissue.

Glucose 6-phosphatase

An enzyme in the liver that removes the phosphate from glucose 6-phosphate, allowing glucose to be released into the bloodstream.

Insulin

A hormone that decreases glycogen degradation when blood glucose levels rise.

Glucagon

A hormone that promotes glycogen degradation during periods of starvation to increase blood glucose levels.

Epinephrine

A hormone that increases during exercise and stress, promoting the mobilization of glucose from glycogen for muscle use.

cAMP (cyclic AMP)

A signaling molecule that regulates glycogen degradation, with levels increasing during stress and exercise.

Muscle glycogen

Glycogen stored in muscles, providing an immediate energy source for rapid muscle contraction.

Liver glycogen

Glycogen stored in the liver, serving as a quick source of glucose to maintain blood-glucose levels.

Aerobic metabolism

The process of producing cellular energy in the presence of oxygen, for which muscle glycogen is used.

Anaerobic metabolism

The process of producing energy without oxygen, during which muscle glycogen may also be utilized.

Glycolytic pathway

The metabolic pathway that converts glucose into pyruvate, producing energy in the form of ATP.

Phosphorolysis reaction

A reaction involving the cleavage of a glycosidic bond in glycogen by an inorganic phosphate, resulting in glucose 1-phosphate.