Glycogen metabolism Flashcards Preview

MCBM > Glycogen metabolism > Flashcards

Flashcards in Glycogen metabolism Deck (27):
1

Glucagon promotes glygocen _____

breakdown to glucose and release of glucose into the bloodstream

2

Why is GLUT 4 impt

Insulin dependent found in skeletal muscle and adipose

3

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

phosphorolate -->Glucose 6 -phosophate

4

NADPH is used for ____reactions

anabolic; synthesizes things.

5

NADH is used for ____things

catabolic; breaking things down

6

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

storage; liver; 12-24 hours

7

fed state-->insulin inc-->

glycogen synthesis

8

hunger-->glucagon increases-->

glycogen breakdown

9

What are the 3 enzymes involved in glycogen breakdown

1. glygocen phosphorylase
2. Debranching enzyme
3. Phosphoglucomutase

10

What is the action of glycogen phosphorylase

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

11

What is the action of phosphoglucomutase

Converts glucose 1 -phosphate to glucose 6- phosphate

12

What is the action of debranching enzyme

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.

13

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

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

14

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

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

15

What does the UDP carrier molecule provide

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

16

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

UDP - glucose + PPi

17

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

non reducing

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.

11

19

What is glycogen core

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

20

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

primer;

21

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

breakdown

22

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

synthesis; glycogen synthase kinase.
phosphoprotein phosphatase 1 (PP1)

23

PKA activates ____which phosphorolates ____
and converts it to phosphorolase a. Now we can breakdown glygcogen to release it in the bloodstream.

phosphorylasekinase; phosphorolate b

24

The enzyme that phosphoralates Glycogen is called

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

25

Stopping the inactivation of glycogen by

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

26

Glucagon activates ___ and favors glycogen breakdown (glycogenolysis)

PKA

27

Insulin activates ____ and ___ and favors glycogen synthesis

PKB; PP1