Lecture 14

Question 1

Glycogen description

Answer 1

large and branched polymer of glucose residue glucose storage in the liver and muscle

glucose buffer! the reason we don’t wake up hypoglycemic

Question 2

glycogenin is ____ protein

Answer 2

nucleating protein

Question 3

Answer 3

glycogenin in the middle surrounded by glucose branches

Question 4

how much glycogen can be stored in a granule?

Answer 4

300 g

Question 5

linear bonds of glycogen

Answer 5

α 1-4 chains

Question 6

branched bonds of glycogen

Answer 6

α 1-6

Question 7

how to make glycogen

Answer 7

1. attach a good LG: UDP Glucose because it basically gets added to glucose to enable adding of more glu groups
2. add to the growing chain

Question 8

role of glycogenin

Answer 8

adds 1st glucose in glycogen synthesis

Question 9

glycogen synthase role in glycogen syth

Answer 9

adds more glucose in α1,4 linkages

Question 10

branching enzyme role in glycogen synth

Answer 10

creates branching α1,6 linkages

Question 11

UDP glucose role in glycogen syth

Answer 11

basically gets added to glu easily and thus can keep adding

Question 12

Glycogen-branching enzyme

Answer 12

convers α1,4 branching to α1,6 linkage creating branching, which leads to efficiency in glucose release

Question 13

How to break down glycogen

Answer 13

1. phosphorylation of the chain by glycogen phosphorylase (GP)
2. glu-6P → glu-1P

Question 14

Phosphoglucose mutase

Answer 14

PGM

converts Glu-1P to Glu-6P

Question 15

Role of glycogen phosphorylase in breakdown of glycogen

Answer 15

basically phosphorylating the chain

Question 16

why is glycogen broken down?

Answer 16

to replenish blood glucose levels after activity

Question 17

glycogen break down

liver vs. muscle

Answer 17

liver: ATP used in synthesis of glucose during recovery Glu-6P→glucose with enzyme: Glu-6P ase

muscle: no Glu-6P ase, ATP produced by glycolysis

Question 18

regulation of Glycogen synthase

Answer 18

insulin & glucose= activate

glucagon= inhibits

Question 19

regulation of Glycogen phosphorylase

Answer 19

glucagon= activates

insuling & glucose = inhibits

Question 20

active when it is phosphorylated, inactive when unphosphorylated

Answer 20

Glycogen synthase

Question 21

inactive when phosphorylated and active when unphosphorylated

Answer 21

glycogen synthase

Question 22

important points for glycogen phosphorylase regulation

Answer 22

1. blood glucose musht stay @ critical levels
2. glucagon’s actions are through phosphorylation

Question 23

everything by phosphorylation

Answer 23

glucagon!

Question 24

important glucostat

Answer 24

the liver!

Question 25

glucagon stimulates

Answer 25

gluconeogenesis & glycogen breakdown

Question 26

glucagon inhibits

Answer 26

glycogen synthesis & glycolysis

Question 27

insulin inhibits

Answer 27

glycogen breakdown & gluconeogenesis

Question 28

insulin stimulates

Answer 28

glycolysis & glycogen synthesis

Question 29

β cells release

Answer 29

insulin when glucose is high