W11 Glucogenesis and glycogenesis

Question 1

what is glycogenolysis

Answer 1

breakdown of glycogen to glucose-1-phosphate and glucose

Question 2

where does gylcogenolysis occur

Answer 2

hepatocytes (liver)
myocytes (skeletal muscles msucle cells)

Question 3

what is glycogen used for

Answer 3

aerobic and anaerobic metabolisms

Question 4

where is glycogen as a energy stored

Answer 4

liver

Question 5

what are the 3 enzymes for gylcogenolysis

Answer 5

glycogen phosphorylase
glycogen debranching enzyme
phosphoglucomutase

Question 6

how does glycogen phosphorylase catalyse a reaction

Answer 6

inorganic phosphate will attack non-reducing end of glycogen

Question 7

what are the products of glycogenolysis

Answer 7

glucose 1-phosphate and shortened by 1 residue glycogen

Question 8

when does gylcogenolysis end

Answer 8

when it reaches 4 glucose residues away from a branch point

Question 9

for further glycogenolysis what debranching enzyme is needed

Answer 9

1->6 glucantransferase

Question 10

what needs to be hydrolyses for glycogen phosphorylase activity to continue

Answer 10

C-6 of glycosyl residue

Question 11

what is glucose 1-phosphate converted to at the end of glycogenolysis

Answer 11

glucose 6-phosphate

Question 12

what does glucose 6-phosphatase do

Answer 12

converts glucose 6-phosphate to glucose in the liver when blood glucose is low

Question 13

what is acetyl CoA catalysed by

Answer 13

pyruvate dehydrogenase

Question 14

what is the point of pyruvate into the TCA

Answer 14

oxidation of glucose to CO2
incorporated into lipids

Question 16

how is the conversion of pyruvate to acetyl CoA regulated

Answer 16

phosphorylation
high concs of NADH

Question 18

what activates and deactivates PDH

Answer 18

kinase = activate
phosphatase = deactivate

Question 19

what increases phosphorylation and activation of PDH

Answer 19

more NADH
acetyl CoA
ATP/ADP

Question 20

what are the 2 primary control points of TCA

Answer 20

isocitrate dehydrogenase
a-ketoglutarate dehydrogenase

Question 21

what is a-ketoglutarate used for

Answer 21

glutamate

Question 22

what does isocitrate dehydrogenase do

Answer 22

increase enzyme affinity to substrate

Question 23

what is glycogenesis

Answer 23

adding glucose to chains of glycogen for storage

Question 24

how is the cori cycle activated

Answer 24

insulin during high glucose levels

Question 25

what is the substrate for polymerisation of monosaccharides

Answer 25

NTP-glucose

Question 26

how is glucose converted to glucose 6-phosphate

Answer 26

hexokinase enzyme in liver

Question 27

how is glycogen synthesis begun

Answer 27

glucose 6-phosphate is converted to glucose 1-phosphate by phosphoglucomutase

Question 29

what is glucose 1-phosphate converted to and by

Answer 29

UDP-glucose by UDP-glucose pyrophosphorylase

Question 30

what is UDP-glucose

Answer 30

a sugar nucleotide

Question 31

what is the primer protein for glycogen branching

Answer 31

glycogenin

Question 32

what catalyses the reaction of UDP-glucose and glycogenin

Answer 32

glucosyltransferase

Question 33

what enzyme also extends the chain of glycogen

Answer 33

glucogenin

Question 34

when does glycogen synthase take over glcogenin

Answer 34

after 7 glucose resiudes

Question 35

which enzyme is used for branching points of glycogen

Answer 35

glycosyl (4->6) transferase

Question 36

what is gluconeogenesis for

Answer 36

converting of glucose 6-phosphate to ribose 5-phospahte

Question 37

which 2 activities of glycogen happen in fast twitch muscle fibres

Answer 37

glycogenolysis glycolysis

Question 38

which 3 stores give glyconengensis substrates

Answer 38

lactate AA glycerol

Question 39

what does fructose 1,6 diphosphatase do

Answer 39

hydrolysis of phosphate from C1

Question 40

which enzyme is used for reverse reaction of phosphate removal in fructose-6-P

Answer 40

phosphofructokinase

Question 41

which 2 enzymes act as antagonistic pair for glycolysis or gluconeogenesis

Answer 41

PFK-1 PBPase-1

Question 42

for glycogen extension where does glucose join

Answer 42

reducing end

Question 43

what are glucose residue in glycogen linked by

Answer 43

a(1->4) glycosidic bonds

Question 45

where does glucogenesis normally occur

Answer 45

in the liver sometimes kidney

Question 46

what is oxaloacetate process for

Answer 46

converting pyruvate into PEP

Question 47

which 2 enzymes catalyse oxaloacetate

Answer 47

pyruvate carboxylase phosphoenolpyruvaye

Question 48

where does oxaloacetate occur

Answer 48

in the mitochondria

Question 49

what is oxaloacetate reduced to

Answer 49

malate

Question 50

what deoxidises malate to oxaloacetate

Answer 50

cytoplasm NADH

Question 51

where is glucose 6-phosphate transported to

Answer 51

ER

Question 52

what happens after PEP hydrolysis

Answer 52

hydrolysis of fructose 1,6-biphosphate