GGG- Corso

Which GLUT transporters are insulin sensitive?

GLUT4

What cells use GLUT1 transporters? GLUT2? GLUT3? GLUT4? GLUT5?

GLUT1- RBCs, most other cells

GLUT2- liver, pancreas (b-cells) , intestines

GLUT3- brain

GLUT4- skeletal muscle, adipose tissue

GLUT5- lumen side of intestine

How is glucose trapped in cells?

Glucose can freely enter/leave cells, but once converted to G6P (glucose-6-phosphate) it cannot leave!

What 2 enzymes can convert glucose to glucose-6-phosphate?

• hexokinase- in most cells

• glucokinase- liver, pancreas, kidneys

A hexokinase deficiency causes what disease?

hemolytic anemia

A glucokinase deficiency causes what disease?

MODY

Briefly describe how glycogen is synthesized:

1. glucose—>G6P using hexo/glucokinase

2. G6P—>G1P using phosphoglucomutase

3. G1P—> UDP-G using UDP-glucose pyrophosphorylase

4. UDP-G—>glycogen using glycogen synthase

5. glycogen—> more compact glycogen using branching enzyme

A branching enzyme deficiency causes what?

Anderson’s disease

Symptom of Anderson’s disease:

enlarged liver

A glycogen synthase deficiency causes what?

Type 0 glycogen storage disorder

Symptoms of type 0 glycogen storage disorder:

• hypoglycemia

• muscle weakness

Describe the breakdown of glycogen:

1. debranch glycogen using debrancher enzyme

2. glycogen—>G1P using glycogen phosphorylase

3. G1P—>G6P

4. G6P —> glucose using glucose-6-phosphatase

When the debranching enzyme doesn’t work we have what disease?

Cori’s disease (type III) (think the opposite of Anderson’s)

What are the symptoms of Cori’s disease?

• liver enlargement

• hypoglycemia

• muscle weakness

A problem in glycogen phosphorylase can cause what 2 diseases? (name their types as well)

• Hers disease (type VI)

• McArdle’s disease (type V)

What are the symptoms of Hers Disease?

• liver enlargement

• hypoglycemia

What are the symptoms of McArdle’s disease?

muscle weakness

When the glucose-6-phosphatase doesn’t work it causes what disease? (name the type as well)

Von Gierke disease (type 1)

What are symptoms of Von Gierke’s disease?

hypoglycemia

For each of the following glycogen-storage disease’s name their “type”/number:

• Cori’s disease

• Her’s disease

• Von Gierke’s disease

• McArdle’s disease

• Cori’s disease- type III

• Her’s disease- type VI

• Von Gierke’s disease- type I

• McArdle’s disease- type V

How do glucagon and insulin affect glycolysis?

glucagon- inhibits

insulin- promotes

What steps of glycolysis are irreversible? These are also the same steps that insulin and glucagon act on.

1, 3, 10

A deficiency in the enzyme phosphofructokinase or PFK-1 would cause what?

Tarui’s (type VII GSD)

In step 4 of glycolysis, what enzyme is responsible for converting G6P to G3P and DHAP?

aldolase

Aldolase B deficiency in the liver causes…

fructose intolerance

Step 6 of glycolysis is converting G3P to 1,3-bisphosphoglycerate. What vitamin is required for this reaction to occur?

NIACIN

Step 6 of glycolysis (conversion of G3P to 1,3-bisphosphoglycerate) can be poisoned by what compound?

Arsenate/Arsenic

The last step of glycolysis produces ATP. What enzyme is responsible for producing this ATP?

pyruvate kinase

A pyruvate kinase deficiency causes…

hemolytic anemia

Review of deficiencies in glycogen:

1. Branching enzyme- Anderson’s disease

2. Glycogen Synthase- type 0 glycogen storage disorder

3. Hexokinase- hemolytic anemia

4. glucokinase- MODY

5. debranching enzyme- Cori’s disease (Type III)

6. glycogen phosphorylase- Hers (type VI) and McArdle’s (Type V)

7. glucose-6-phosphate- Von Gierke Disease (Type I)

Review of deficiencies in glycolysis:

1. glucokinase- MODY

2. hexokinase- Hemolytic anemia

3. PFK-1- Tauri’s/ type VII GSD

4. Aldolase B- fructose intolerance

5. Glyceraldehydre-3-phosphate dehydrogenase

6. pyruvate kinase- hemolytic anemia

What is the ultimate electron acceptor of the ETC?

oxygen

What are the carbon sources of gluconeogenesis?

• glycerol

• lactate

• alanine

• other amino acids