Glycogen Metabolism | Glycogenolysis | Pathway, Enzymes and Regulation

The video tutorial covers glycogenolysis, explaining its advantages as a rapid energy source and its ability to generate ATP anaerobically. It also discusses the disadvantages, such as limited ATP yield per mass and storage capacity. The roles of glycogen in muscle and liver are highlighted, with a focus on energy provision and blood glucose maintenance. Key enzymes like glycogen phosphorylase and debranching enzyme are detailed, along with their regulatory mechanisms involving insulin and glucagon. Differences in glycogen metabolism between liver and muscle are explored, emphasizing gluconeogenesis and glycolysis. The tutorial concludes by explaining why glycogen yields more ATP compared to non-glycogen glucose.

What is one of the main advantages of glycogenolysis?

• It can be used as a rapid energy source.

• It requires oxygen to generate energy.

• It has an unlimited storage capacity.

• It produces more ATP per mass than adipose tissue.

How does glycogen function in the liver?

• To maintain blood glucose levels.

• To produce ketone bodies.

• As a rapid energy source during exercise.

• To store fat.

Which enzyme initiates glycogenolysis?

• Glycogen phosphorylase

• Glycogen synthase

• Phosphoglucomutase

• Glucose 6 phosphatase

What is the role of the debranching enzyme in glycogenolysis?

• It hydrolyzes A1-4 glycosidic bonds.

• It transfers residues and hydrolyzes A1-6 bonds.

• It synthesizes glycogen.

• It phosphorylates glucose.

How does insulin affect glycogen synthase?

• It inhibits glycogen synthase.

• It has no effect on glycogen synthase.

• It degrades glycogen synthase.

• It activates glycogen synthase.

What effect do glucagon and epinephrine have on glycogen phosphorylase?

• They inhibit glycogen phosphorylase.

• They activate glycogen phosphorylase.

• They have no effect on glycogen phosphorylase.

• They degrade glycogen phosphorylase.

In skeletal muscle, what activates glycogen phosphorylase during exercise?

• Calcium

• ATP

• Insulin

• Glucose

What is the role of AMP in muscle glycogenolysis?

• It inhibits glycogen phosphorylase.

• It converts glucose to glycogen.

• It activates glycogen phosphorylase.

• It deactivates glycogen synthase.

Why does glycogen-derived glucose yield more ATP than free glucose?

• It is stored in larger quantities.

• It requires less oxygen.

• It is more easily absorbed.

• It is already phosphorylated.

What is the primary use of glucose 6 phosphate in the liver?

• Protein synthesis

• Fat synthesis

• Gluconeogenesis

• Glycolysis