Glycogen Metabolism: Glycogenolysis and Glycogenesis

These flashcards cover key vocabulary and concepts related to glycogen metabolism, including glycogenolysis and glycogenesis.

Glycogen

Storage form of glucose; a polymer of glucose linked by α-1,4 and α-1,6 glycosidic bonds.

Glycogenolysis

The breakdown of glycogen into glucose-1-phosphate or glucose.

Glycogenesis

The synthesis of glycogen from glucose.

Glycogen Phosphorylase

Key enzyme that breaks α-1,4 glycosidic bonds in glycogen, using inorganic phosphate.

Phosphoglucomutase

Enzyme that converts glucose-1-phosphate to glucose-6-phosphate in a reversible reaction.

Debranching Enzyme

Enzyme responsible for removing α-1,6 bonds in glycogen during breakdown.

Glycogen Synthase

Key enzyme that adds glucose to non-reducing ends of glycogen and forms α-1,4 bonds.

Glycogenin

Self-glucosylating protein that serves as a primer for glycogen synthesis.

Von Gierke Disease

A glycogen storage disease caused by deficiency of glucose-6-phosphatase, leading to severe hypoglycemia.

Pompe Disease

Glycogen storage disease resulting from deficiency of lysosomal α-1,4-glucosidase.

Cori Disease

Condition caused by a debranching enzyme deficiency leading to abnormal glycogen accumulation.

McArdle Disease

Muscle glycogen phosphorylase deficiency characterized by exercise intolerance and muscle cramps.

Insulin

Hormone that regulates glycogen synthesis, increasing glycogenesis and decreasing glycogenolysis.

Glucagon

Hormone that stimulates glycogen breakdown during fasting, leading to increased blood glucose.

Allosteric Regulation

Regulatory mechanism where the binding of metabolites (like AMP) alters enzyme activity.

Covalent Regulation

Regulatory mechanism involving phosphorylation and dephosphorylation to control enzyme activity.

Branching Enzyme

Enzyme that creates α-1,6 bonds in glycogen, increasing its solubility and synthesis rate.