Glycogen Metabolism

Question 1

What are the main stores of glycogen?

Answer 1

Liver and skeletal muscle

Question 2

Structure of glycogen

Answer 2

Branched chain polysaccharides Made from alpha glucose
The primary glycosidic bind in an alpha 1,4 linkages
After every 8 -10 gkycosidic residue, there is a branch containing and alpha I,6

Question 3

A glycogen molecule can have a weight of

Answer 3

108 daltons

Question 4

Synthesis of glycogen

Answer 4

Synthesized from D glucose in the cytosol and uses energy in the form of ATP and UTP

Question 5

Synthesis of UTP

Answer 5

Alpha D glucose attached to uridine phosphate is the source of the glucosyl residues that are added to the growing glycogen molecule.

Question 6

UDP glucose is synthesized from glucose 1- phosphate and glucose by the enzyme?

Answer 6

UDP glucose pyrophosphorylase

Question 7

Glucose 1- phosphate is synthesis from glucose 6 phosphate by

Answer 7

Phosphoglucomutase

Question 8

The high energy bond in PPi is hydrolyzed by

Answer 8

pyrophosphatase

Question 9

Inter conversion of glucose 6 phosphate and glucose 1 phosphate is done by

Answer 9

Phosphoglucomutase

Question 10

Which enzyme makes the alpha 1-4 bonds in glycogen?

Answer 10

Glycogen synthase

Question 11

This enzyme can acts as an acceptor of glucose residues from UDP glucose

Answer 11

Glycoenin

Question 12

Elongation of glycogen chains

Answer 12

Elongation of a glycogen chain involves the transfer of glucose from UDP- glucose to the non reducing end of the growing chain forming a new gkycosidic bond between the anomeric hydroxyl Of carbon 1 of the activated glucose and carbon 4 of the accepting glycogen residue.

Question 13

What increases the rate of gkycogen synthesis?

Answer 13

The branching of the glycogen, gives it more souble and increases the number of non reducing end where new glucosyl residues can be added .

Question 14

Which enzymes makes branches?

Answer 14

Amylo- alpha (1,4), alpha (1,6) transglucosidase

Question 15

In degradation , glycogen is degraded to glucose 1 phosphate by th breaking of

Answer 15

Alpha 1,4 bonds

Question 16

The cleaving of the alpha (1,4) glycosidic bonds between the glucosyl residues at the on reducing ends of the glycogen chain producing glucose 1 phosphate is done by?

Answer 16

Glycogen phosphorylase

Question 17

Four glucosyl units on each chain that can be degraded any longer is called

Answer 17

A limit dextrin

Question 18

The removal of branches by a two enzymatic of a single bifunctional protein is done by

Answer 18

The debranching enzyme

Question 19

The outer three of the four glucosyl residues attached at a branch is done by

Answer 19

Oligo (1,4) glycan transferase activity

Question 20

The remaining single chain is attached to the (1,6) linkage is removed hydroltically by

Answer 20

Amylo alpha (1,6) glucosidase activity

Question 21

Which enzyme transports glucose 6 phosphate into the ER

Answer 21

Glucose 6 phosphate translocase

Question 22

The regulated enzyme in glucogenesis is

Answer 22

Glycogen synthase

Question 23

Protein phosphatase 1 Is stimulated by

Answer 23

Insulin