Lecture 19

Question 1

glucose is stored as what in humans

Answer 1

glycogen

Question 2

reasons for storing glucose as glycogen

Answer 2

breakdown can provide energy for muscle very quickly, liver stored glycogen can regulate blood glc levels, some muscles and cells have to have glucose

Question 3

level 1 structure of glycogen

Answer 3

1-4 alpha glycosidic linkage

Question 4

level 2 structure of glycogen

Answer 4

beta particle

Question 5

level 3 structure of glycogen

Answer 5

alpha particles

Question 6

breakdown of cellular glycogen to glucose 1 phosphate

Answer 6

glycogenolysis

Question 7

synthesis of glycogen

Answer 7

glycogenesis

Question 8

first step of glycogenesis

Answer 8

glucose to glucose 6 phosphate

Question 9

enzyme in first step of glycogenesis

Answer 9

hexokinase

Question 10

second step in glycogenesis done by what

Answer 10

phosphoglucomutase

Question 11

second step in glycogenesis

Answer 11

glucose 6phos -> glucose 1,6 bisphos -> glucose 1 phos

Question 12

what does third step in glycogenesis start with

Answer 12

sugar phosphate + NTP

Question 13

what does third step in glycogenesis end with

Answer 13

UDP glucose pyrophosphorylase enzyme, pyrophosphate

Question 14

enzyme in third step of glycogenesis

Answer 14

NDP sugar phosphorylase

Question 15

what happens after third step of glycogenesis

Answer 15

elongation of glycogen chains

Question 16

catalyzes formation of alpha 1-6 bonds found at branch points of glycogen cleaves off part of existing straight glycogen chain

Answer 16

glycogen branching enzyme

Question 17

what does glycogen synthase require

Answer 17

a primer

Question 18

primer on which new chains are assembled and the enzyme that catalyzes their assembly

Answer 18

glycogenin

Question 19

what does glycogenin use as a substrate

Answer 19

UDP glc

Question 20

catalyzes phosphorolytic cleavage at the nonreducing ends of glycogen ends of glycogen chains

Answer 20

glycogen phosphorylase

Question 21

what does glycogen phosphorylase break down

Answer 21

alpha 1-4 glc bonds

Question 22

what does glycogen phosphorylase yield

Answer 22

GLC 1- phos

Question 23

what does glycogen phosphorylase require

Answer 23

pyridoxal phosphate

Question 24

how many glc units in one molecule of glycogen

Answer 24

55000

Question 25

transfers branches onto main chains and releases residue at 1-6 alpha branch as FREE clc

Answer 25

debranching enzyme

Question 26

catalyzes reversible rxn from glucose 1 phos to glucose 6 phos

Answer 26

phosphoglucomutase

Question 27

what happens to glucose 6 phos in muscle

Answer 27

enters glycolysis

Question 28

what happens to glucose 6 phos in liver

Answer 28

converted to glucose to regulate blood glucose levels

Question 29

hormone that creates glycogen

Answer 29

insulin

Question 30

anabolic high blood clc homorne

Answer 30

insulin

Question 31

what does insulin activate

Answer 31

phosphoprotein phosphates, glycogen synthase

Question 32

what does insulin inactivate

Answer 32

glycogen phosphorylase

Question 33

breaks down glycogen

Answer 33

glucagon

Question 34

glycogen activates what

Answer 34

protein kinases, glycogen phosphorylase

Question 35

glucagon inactivates what

Answer 35

glycogen synthase

Question 36

2 forms of glycogen synthase

Answer 36

glycogen synthase a and B

Question 37

which form of glycogen synthase is unphosphorylated and catalytically active

Answer 37

a

Question 38

which form of glycogen synthase is phosphorylated and inactive unless glucose 6phos is present

Answer 38

b

Question 39

catalyzes phosphorylation of glycogen synthase a

Answer 39

glycogen synthase kinase 3

Question 40

insulin does what to GSK3 and PP1

Answer 40

inactivates GSK3, activates PP1

Question 41

GSK3 adds what

Answer 41

3 phosphates from ATP

Question 42

2 forms of skeletal glycogen phosphorylase

Answer 42

glycogen phosphorylase a and b

Question 43

which form of glycogen phosphorylase is catalytically active

Answer 43

a

Question 44

what two things trigger phosphorylation of phosphorylase b

Answer 44

epinephrine and glucagon

Question 45

signal for muscle contraction

Answer 45

Ca2+

Question 46

what does Ca2+ bind to

Answer 46

phosphorylase b kinase

Question 47

what accumulates in contracting muscle

Answer 47

AMP

Question 48

removes phosphoryl groups from phosphorylase a, converting it to phosphorylase b

Answer 48

phosphoprotein phosphatase 1

Question 49

which is a glucose sensor

Answer 49

liver glycgen phosphorylase A

Question 50

sequence of enzymatic rxns in which a catalyst aactivates a catalyst activates a catalyst

Answer 50

enzyme cascade

Question 51

rise in cAMP activates what

Answer 51

PKA

Question 52

catalyzes phosphorylation of glycogen phosphorylase b

Answer 52

phosphorylase b kinase