1: Glycogenesis And Glycogenolysis

Question 1

Glycogen linkages - straight and branching

Answer 1

Straight: a-1,4 glycosidic bonds

Branch points: a-1,6 glycosidic bonds

Question 2

Non-reducing vs reducing end of glycogen

Answer 2

Non-reducing: terminal glucose with a free OH group at C4

Reducing end: attached to glycogenin

Question 3

Glycogenin

Answer 3

Creates a short polymer on itself to serve as a primer for glycogen

Question 4

Purpose of liver vs muscle glycogen

Answer 4

Liver: regulation of blood glucose levels
Muscle: provides reservoir of fuel for activity

Question 5

Granule of glycogen

Answer 5

Glycogen + enzymes needed for glycogen metabolism

Question 6

In glycogenesis, when is a fragment broken off to create a branch?

Answer 6

When a glycogen chain reaches 11 residues in length

Question 7

Why glycogen branching is important

Answer 7

Increases non-reducing ends -> increases glycogen solubility

Question 8

What enzyme are muscles lacking (compared to liver) that makes it so free glucose cant form and leave the cell?

Answer 8

Glucose-6-phosphatase

Question 9

In glycogenolysis chain shortening, when does glycogen phosphorylase stop working?

Answer 9

When its within 4 residues of a branch point