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Question 1

Which glucose receptor is insulin dependent?

Answer 1

GLUT 4

Question 2

Where does glycolsis take place?

Answer 2

In the cytoplasm

Question 3

What are the enzymes for rxn 1, 3, and 10 in glycolsis?

Answer 3

1: Hexokinase

3: phosphofructokinase-1

10: Pyurvate kinase

Question 4

What happens in rxn 1 of glycolsis?

Answer 4

Hexokinase will add a phosphate from atp on to glucose to form glucose-6-phosphate.

This will trap the glucose inside the cell.

This reaction is feedback inhibted by the accumilation of glucose-6-phosphate.

Question 5

How is rxn1 different in the liver?

Answer 5

It is induced by glucokinase, bc its purpose is to store glucose. (reduce hyperglycemia)

It is not feedback inhibted (bc we want to store as much glucose as possible when needed)

Glucokinase is induced by insulin

Question 6

How is rxn1 different in the pancreas?

Answer 6

It is induced by glucokinase in b cells of pancreas

It is used as a sensor (indicator) for glucose to tell the pancrease to release insulin.

Question 7

What is the difference in affinity and Km for glucose between hexokinase and glucokinase?

Answer 7

Hexokinase: High affinity / Low Km

Glucokinase: Low affinity / High Km

Question 8

What is the difference in Vmax for glucose between hexokinase and glucokinase?

Answer 8

Hexokinase: Low Vmax

Glucokinase: High Vmax (to reduce Hyperglycemia as fast as possible)

Question 9

What happens in Rxn 2?

Answer 9

Glucose 6-phosphate will turn into Fructose-6-phosphate

Question 10

What happens in Rxn 3?

Answer 10

Phosphofructokinase 1 will add another phosphate molecule to Fructose-6-phosphate
turning it into Fructose-1,6-bisphosphate.

This process requires ATP (for the phosphate)

Question 11

What is the most important control point in glycolsis?

Answer 11

Rxn 3

Question 12

What is the rate limiting and comitted step in glycolsis?

Answer 12

Rxn 3

Question 13

What is Rxn 3/phosphofructokinase regulated by?

Answer 13

Rxn 3 is inhibted by the energy level of the cell (The amount of ATP inside the cell)

Question 14

What is Rxn 1/ Hexokinase regulated by?

Answer 14

The amount of glucose inside the cell

Question 15

What are the inhibtors of Rxn 3?

Answer 15

Atp, citrate

Question 16

What are the activators of Rxn 3/phophofructokinase?

Answer 16

AMP

Fructose-2,6-Bisphosphate

Question 17

How does insulin activate PFK1?

Answer 17

It activates it using a mediator called Fructose-2,6-bisphosphate

Question 18

How does insulin activate PFK1 in more detail?

Answer 18

Insulin binds to the recptor on hepatocytes

Insulin activates PFK-2

PFK-2 converts a tiny amount of fructose-6-phosphate to fructose-2,6-bisphosphate

Fructose-2,6-phosphate will activate PFK-1

PFK-1 will turn Fructose-6-phosphate into fructose-1,6-bisphosphate

Question 19

What reaction requires NAD+

Answer 19

Rxn 6

Question 20

What is the enzyme used in Rxn 6?

Answer 20

Glyceraldehyde 3-phosphate dehydrogenase

Question 21

What is the product of Rxn 6?

Answer 21

1,3-Bisphosphoglycerate

(Remember 2,3-BPG )

Remember the 6 hemoglobin molecules in oxy affinity lec

Question 22

What happens in Rxn 7?

Answer 22

1,3-Bisphosphoglycerate Breaks down into 3-Phosphoglycerate to produce 2 ATP (bc it is 2 reactions)

(Substrate level phosphorylation)

Question 23

What is special about Rxn 9?

Answer 23

The enzyme that catalyzez Rxn 9 is Enolase.

Enolase is inhibted by fluoride.

Enolase is used by bacteria to form tooth decay.

Question 24

What happens in Rxn 10?

Answer 24

It is catalyzed by Pyurvate Kinase

It is the second Substrate level phosphorylation reaction (2 ATP is produced)

Third regulated step.

Activated by fructose 1,6-bisphosphate (feed forward activation)

Question 25

What happens to the RBCs bc of pyruvate kinase deficeny? Are there heinz bodies?

Answer 25

Decreased ATP production which leads to the inability of the cell to maintain the ion pumps This inturn leads to the inability of the cell to sustain its membrane Causing the cells to swell and burst. No heinz bodies present

Question 26

What happens to 2,3-Bisphosphoglycerate bc of pyruvate kinase deficeny?

Answer 26

The reaction will go backward bc of the fact that Pyruvate kinase is deficent. This will convert Phosphophenolpyruvate back into 1,3-bisphosphateglycerate which will then be converted to 2,3-BPG. This causes an increase in 2,3-BPG in the body which will decrease the hemoglobin's affinity to oxygen.

Question 27

What are the 3 hormonal regulated reactions? What hormones regulate them?

Answer 27

Rxn 1,3,10.

Question 28

Which enzymes are regulated by phosphorylation?

Answer 28

PFK-2 and Pyruvate kinase

Question 29

Does glycolsis require oxygen?

Answer 29

NO

Question 30

What are the two fates of pyruvate?

Answer 30

Either it will be converted into acytl COA into the electron transport chain **(in cells with mitochondria and enough oxygen)** 2. Pyruvate will be converted into Lactate or ethanol (without oxygen/mitochondria) (fermentation)

Question 31

What are some situations where the body switches to anaerboic glycolsis?

Answer 31

Rigorus exercise in muscle cells (produces lactic acid) High altitude Ischemic cells (to prevent cell death)