Glycogen metabolism

Question 1

Glucagon promotes glygocen _____

Answer 1

breakdown to glucose and release of glucose into the bloodstream

Question 2

Why is GLUT 4 impt

Answer 2

Insulin dependent found in skeletal muscle and adipose

Question 3

Once glucose is in cell we_____it, to keep it in the tissue

Answer 3

phosphorolate –>Glucose 6 -phosophate

Question 4

NADPH is used for ____reactions

Answer 4

anabolic; synthesizes things.

Question 5

NADH is used for ____things

Answer 5

catabolic; breaking things down

Question 6

Glycogen is the _____form of glucose and maintains blood glucose and is stored in the ____. It is depleted within

Answer 6

storage; liver; 12-24 hours

Question 7

fed state–>insulin inc–>

Answer 7

glycogen synthesis

Question 8

hunger–>glucagon increases–>

Answer 8

glycogen breakdown

Question 9

What are the 3 enzymes involved in glycogen breakdown

Answer 9

1. glygocen phosphorylase
2. Debranching enzyme
3. Phosphoglucomutase

Question 10

What is the action of glycogen phosphorylase

Answer 10

cleavess glucose via phosphorolysis sequentially from NR end releasing glucose 1 -phosophate

Question 11

What is the action of phosphoglucomutase

Answer 11

Converts glucose 1 -phosphate to glucose 6- phosphate

Question 12

What is the action of debranching enzyme

Answer 12

a bifunctional enzyme. The first action (transferase) transfers 3 glucose residues to main chain. Its second activity (alpha 1-6 glucosidase) is to cleave the next bond and release residue as a free glucose.

Question 13

Glucose 6-phosphate now needs to be ____to leave the cell.

Answer 13

dephosphorolated; Glucose 6 phosphatase converts glucose 6 phosphate to free glucose in the liver

Question 14

What are the 3 enzymes required for glycogen synthesis (glycogenesis)

Answer 14

1. UDP-glucose pyrophosphorylase
2. Glycogen synthase
3. Amylo(1–>4) to (1–>6) transglycosylase (glycogen branching enzyme)

Question 15

What does the UDP carrier molecule provide

Answer 15

Binding oppurtunities which helps to decrease the activation energy and releases PPi which can be hydrolized to provide energy to drive reaction forward.

Question 16

UDP glucose pyrophosphorylase catalyzes the reaction of glucose 1- phosphate + UTP to

Answer 16

UDP - glucose + PPi

Question 17

Glycogen synthase adds glucose from UDP-glucose carrier to _____end of growing glycogen chain

Answer 17

non reducing

Question 18

Glycogen branching enzyme catalyzes the transfer of 6-7 glucose residues from a chain of at least ____ glucose residues long to the C-6 OH group of an interior glucose on the same or nearby chain, thus producing a branch.

Answer 18

11

Question 19

What is glycogen core

Answer 19

A protein with primer glycogens added. Glycogen synthase cant start from nothing.

Question 20

Glycogenin provides a _____and is the core protein of glycogen as well as a bifunctional enzyme.

Answer 20

primer;

Question 21

Glycogen phosphorlylase catalyzes the ____of glycogen and is activated by _____. It is inactivated by phosphoprotein phosphatase 1 (PP1)

Answer 21

breakdown

Question 22

Glycogen synthase catalyzes the _____of glycogen. It is inactivated by phosphorylation via _____. It is activated by dephosphorylation via _____

Answer 22

synthesis; glycogen synthase kinase.

phosphoprotein phosphatase 1 (PP1)

Question 23

PKA activates ____which phosphorolates ____

and converts it to phosphorolase a. Now we can breakdown glygcogen to release it in the bloodstream.

Answer 23

phosphorylasekinase; phosphorolate b

Question 24

The enzyme that phosphoralates Glycogen is called

Answer 24

glycogen synthase kinase. It is a target for Protein Kinase B which is also activated by insulin.

Question 25

Stopping the inactivation of glycogen by

Answer 25

glycogen synthase kinase and reactivating any inactive glycogen synthase by taking phosphate groups off by PP1

Question 26

Glucagon activates ___ and favors glycogen breakdown (glycogenolysis)

Answer 26

PKA

Question 27

Insulin activates ____ and ___ and favors glycogen synthesis

Answer 27

PKB; PP1