W3-2: Glycogen metabolism Flashcards Preview

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Flashcards in W3-2: Glycogen metabolism Deck (19):
1

Linear glycogen is bonded at which glucose carbons?

1 (phosporylated) --> 4

2

Branched glycogen is bonded at which glucose carbons?

1 phosphorylated --> 6

3

Glc activation for glycogen synthesis

4

Glycogen synthesis occurs in which direction?

1' to 4'

5

Branching enzyme name

glycosyl 4-->6 transferase

6

About how many Glc molecules can be added at a branch point?

~11

7

What is the benefit of having so many branch points?

more loose ends are available to be cleaved off the glycogen molecule

and

increases solubility (more --OH groups)

8

Enzyme that cleaves Glc off glycogen

glycogen phosphorylase

9

Two debranching enzymes

4:6 transferase

**moves all but one sugar**

 

α-1,6-glucosidase

**frees last Glc**

10

Two enzymes that control glycogen synthesis/breakdown and regulation

11

Glucagon and Epi action: fasting hepatocyte

12

Insulin action: fed hepatocyte

PHOSPHORYLASE

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13

Epi action: fasting skeletal muscle

PHOSPHORYLASE

14

Insulin action: fed skeletal muscle

15

GSD 0

Glycogen synthase deficiency

16

GSD I (van Gierke disease)

Glucose-6-phosphatase deficiency

(cannot remove Glc from liver)

17

GSD III (Cori disease)

1,6-glucosidase activity deficincy

(cannot remove single sugar)

18

GSD IV

4:6-transferase defiency

fatal

19

GSD V (McArdle disease)

Muscle glycogen phosphorylase deficiency

-->exercise intolerance