E2 Fructose & Glycogen; Glycogen storage diseases

Question 1

What organ is the primary site of fructose disposal?

Answer 1

liver

Question 2

The liver is the primary site of ______ disposal.

Answer 2

fructose

Question 3

What percentage of fructose if extracted by the liver?

Answer 3

70%

Question 4

What two enzymes, that are highly expressed in the liver, are essential for fructose metabolism?

Answer 4

1. Fructokinase

2. Triokinase

Question 5

If a low-dose of fructose is added to a meal containing glucose, what are three outcomes?

Answer 5

1. improved glucose tolerance
2. fructose stimulates glucokinase
3. threefold increase in net glycogen synthesis

Question 6

T/F. Small amounts of fructose can cause the release of hexokinase from a regulatory protein.

Answer 6

False; glucokinase (liver)

Question 7

How does fructose release glucokinase from a regulatory protein?

Answer 7

F-1-P binds to the regulatory protein causing glucokinase to be set free and be activated

Question 8

T/F. Fructose has a high benefit for muscle glycogen synthesis.

Answer 8

False; no benefit

Question 9

Will high or low doses of fructose increase liver glycogen synthesis?

Answer 9

low doses

Question 10

Are high levels of fructose good for the liver?

Answer 10

NO!

Question 11

Why are high levels of fructose not good for the liver?

Answer 11

1. liver has a high uptake

2. increased fat, lactate, and glycerol formation

Question 12

T/F. HFCS and sucrose are not that different than fructose.

Answer 12

True

Question 13

Are glycogen storage diseases genetic or developed?

Answer 13

genetic

Question 14

What causes glycogen storage diseases?

Answer 14

1. enzyme deficiencies (glycogenolysis, glycogenesis)

2. abnormal structure

Question 15

T/F. Glycogen storage diseases have increased storage but same breakdown.

Answer 15

False; increased storage but impaired breakdown

Question 16

Do Glycogen storage diseases have a large or small spectrum when it comes to being mild or fatal?

Answer 16

large spectrum

Question 17

What are the three categories of glycogen storage disease?

Answer 17

1. liver
2. skeletal muscle
3. alpha-glucosidase or debranching enzyme deficiency

Question 18

Glycogen storage diseases will lead to what type of enzyme deficiencies in the liver?

Answer 18

glycogenolysis

Question 19

Glycogen storage diseases in the liver can lead to _______.

Answer 19

hypoglycemia

Question 20

Glycogen storage diseases and what other factor will cause hypoglycemia?

Answer 20

enlarged liver

Question 21

What is an example of a glycogen storage disease in the liver?

Answer 21

von Gierke disease

Question 22

T/F. von Gierke disease is a Type II glycogen storage disease.

Answer 22

False; Type I

Question 23

Glycogen storage disease will lead to what type of enzyme deficiencies in skeletal muscle?

Answer 23

glycogenolysis

Question 24

T/F. Glycogen storage diseases in skeletal muscle will cause glycogenolysis enzyme deficiencies, which in turn will limit glycolysis.

Answer 24

True

Question 25

What are four negative outcomes of glycogen storage diseases in skeletal muscle?

Answer 25

1. low energy production 2. muscle weakness 3. muscle cramping after exercise 4. low lactate levels in blood

Question 26

What is an example of a glycogen storage disease in skeletal muscle?

Answer 26

McArdle disease

Question 27

T/F. The glycogen storage disease alpha-glucosidase/debranching enzyme deficiency can occur in only certain tissues.

Answer 27

False; can occur in many tissues and organs

Question 28

Is the alpha-glucosidase/debranching enzyme deficiency mild or fatal?

Answer 28

Fatal

Question 29

In alpha-glucosidase/debranching enzyme deficiency, where is there an increased storage of glycogen? What does it cause?

Answer 29

increased storage of glycogen in lysosomes of organ causing Cardiomegaly

Question 30

What is an example of an alpha-glucosidase/debranching enzyme deficiency (glycogen storage disease)?

Answer 30

Pompe disease