Glycogen Metabolism/Disorders

Question 1

where is majority of glycogen stored?

Answer 1

liver

Question 2

outside of liver, where else is glycogen?

Answer 2

muscle

Question 3

where in cells does most glycogen reside?

Answer 3

in cytoplasm…but can be in lysosome

Question 4

what is bond that links glucose to each other to form glycogen?

Answer 4

a1,4

Question 5

what is bond that branches glucose in glycogen?

Answer 5

a1,6

Question 6

what is enzyme in charge of linking glucose to form glycogen?

Answer 6

glycogen synthase

Question 7

when does glycogen start being used after feeding?

Answer 7

2-3 hours after meal

Question 8

what does insulin do to glycogen?

Answer 8

inhibits breakdown and promotes synthesis of it

Question 9

what does insulin activate to start glycogen storage?

Answer 9

activates glycogen synthase a

Question 10

what does glucagon do to glycogen?

Answer 10

leads to breakdown of it and inhibits synthesis

Question 11

what enzyme is in charge of taking off glucose from glycogen in glycogen breakdown?

Answer 11

glycogen phosphorylase a

Question 12

what is name of enzyme that transfers branches in glycogen breakdown?

Answer 12

debranching enzyme (4-a-glucanotransferaase)

Question 13

what is name of enzyme that moves the very last branch point glucose to strand of glucose in glycogen break down?

Answer 13

debranching enzyme (a1,6glucosiase-

Question 14

what is name of enzyme in charge of glycogen breakdown in lysosome?

Answer 14

a1,4 glucosidase

Question 15

name the four glycogen storage diseases

Answer 15

Von gierke
pompe
cori
Mcardle

Question 16

type I glycogen storage disease

Answer 16

Von gierke

Question 17

type II glycogen storage disease

Answer 17

pompe

Question 18

type III glycogen storage disease

Answer 18

Curi

Question 19

type IV glycogen storage disease

Answer 19

McArdle

Question 20

what enzyme is deficient in von gierke?

Answer 20

glucose-6-phosphatase

Question 21

explain how glucose-6phosphatase deficiency leads to issues in glycogen storage?

Answer 21

glucose-6-phosphate needs to be changed into glucose to be transported out of the liver and that is done by the phosphatase..if it isnt changed into glucose then it enters the glycogen storage process instead…so lots of glycogen accumulates

Question 22

is blood sugar low or high in von gierke?

Answer 22

hypoglycemia

Question 23

name three things that increase in blood in von gierke

Answer 23

lactate, triglycerides and uric acid

Question 24

why do lactate and uric acid increase in von gierke?

Answer 24

because the glucose 6 phosphate is shunted down the krebs cycle or into the nucleotide cycle and that increases lactate and uric acid respectively

Question 25

what is another disorder associated with von gierke disease?

Answer 25

gout

Question 26

where is glycogen storage increased in von gierke?

Answer 26

liver and kidenys

Question 27

what is enzyme issue in pompe disease?

Answer 27

a-1,4-glucosidase

Question 28

where is issue in pompe disease?

Answer 28

lysosome enzyme

Question 29

name the four main symptoms of pompe disease

Answer 29

cardiomegaly, hypertrophic cardiomyopathy, exercise intolerance, hypotonia

Question 30

what is classic appearance of hypotonic baby?

Answer 30

floppy bby

Question 31

what is enzyme issue in cori disease?

Answer 31

debranching enzymes of glycogen

Question 32

what are the two main symptoms seen in cori disease?

Answer 32

hypoglycemia and hepatomegaly

Question 33

what is cardiac issue in cori disease?

Answer 33

cardiomyopathy

Question 34

what is issue in McArdle disease/

Answer 34

skeletal muscle glycogen phosphorylase

Question 35

where is issue in mcardles disease?

Answer 35

skeletal muscle

Question 36

what is main symptom of mcardles disease?

Answer 36

myopathy/muscle cramps and myoglobinuria

Question 37

what can be seen in urine in mcardles?

Answer 37

myoglobinuria

Question 38

does blood glucose go high or low in mcardles?

Answer 38

unchanged usually

Question 39

what disease is second wind phenomenon assoc with? why?

Answer 39

mcardle bc of increase in muscular blood flow during exercise

Question 40

how are all the glycogen storage diseases inherited?

Answer 40

all are autosomal recessive