Glycogen Phosphorylase Function and Mechanism

The video explains the role of glycogen phosphorylase in breaking down glycogen into glucose-1-phosphate. It details the enzyme's mechanism, highlighting the formation of an oxonium species and the role of phosphate as a nucleophile. The video also discusses the conversion of glucose-1-phosphate to glucose-6-phosphate by phosphoglucomutase, preparing it for glycolysis. The importance of the enzyme's name, glycogen phosphorylase, is clarified, emphasizing its use of phosphate instead of water. The video concludes with a preview of the next topic on glycogen debranching enzymes.

What is the primary function of glycogen phosphorylase in glycogen metabolism?

• To synthesize glycogen from glucose

• To depolymerize glycogen by removing terminal glucose units

• To convert glucose-1-phosphate to glucose-6-phosphate

• To stabilize the glycogen structure

Which molecule is released when glycogen phosphorylase acts on glycogen?

• Glucose-1-phosphate

• Fructose-1-phosphate

• Glucose-6-phosphate

• Glucose

Why is glycogen phosphorylase not classified as a hydrolase?

• It synthesizes glycogen instead of breaking it down

• It does not involve any enzymatic activity

• It uses phosphate instead of water as a nucleophile

• It uses water to remove glucose units

What is the role of phosphoglucomutase in glycogenolysis?

• To synthesize glycogen from glucose

• To phosphorylate glucose

• To break down glycogen into glucose

• To convert glucose-1-phosphate to glucose-6-phosphate

What is the ultimate goal of glycogenolysis in terms of glucose utilization?

• To store glucose as glycogen

• To convert glucose-1-phosphate into glucose-6-phosphate for glycolysis

• To convert glucose into fatty acids

• To produce glucose for immediate energy