Pentose Phosphate Pathway

Question 1

What does the pentose phosphate pathway primarily produce?

Answer 1

Ribose and NADPH

Question 2

What is the main enzyme used in the pentose phosphate pathway?

Answer 2

Glucose 6 phosphate dehydrogenase

Question 3

What is another name for the pentose phosphate pathway?

Answer 3

Hexose monophosphate pathway

Question 4

Where does the hexose monophosphate pathway take place?

Answer 4

Cytosol

Question 5

Is ATP used in the hexose monophosphate pathway?

Answer 5

No ATP is produced or consumed

Question 6

What nitrogenous bases are considered purines?

Answer 6

Guanine and adenine

Question 7

What nitrogenous bases are considered pyrimidines?

Answer 7

Thymine, cytosine, and uracil

Question 8

What is a nucleoside?

Answer 8

Base and a sugar

Question 9

What is a nucleotide?

Answer 9

Base, sugar, and phosphate

Question 10

NADH is oxidized in the electron transport chain to make what?

Answer 10

ATP

Question 11

NADPH is an electron donor during what processes? (Hint: Fantastic Four)

Answer 11

• Reductive biosynthesis
• Respiratory burst
• Detoxification
• Regeneration of antioxidants

Question 12

What are the individual steps of the pentose phosphate pathway in general?

Answer 12

• Dehydrogenation
• Hydrolysis
• Oxidative decarboxylation
• Isomerization

Question 13

What enzymes build a reversible link between the pentose phosphate pathway and glycolysis?

Answer 13

Transketolases and transaldolases

Question 14

What system does the liver utilize to perform detoxification?

Answer 14

P450 monooxygenase system

Question 15

What cellular structure in the liver contains the cytochrome P-450 mono-oxygenase system?

Answer 15

Endoplasmic reticulum

Question 16

The cytochrome P-450 mono-oxygenase system adds hydroxyl groups to what types of compounds?

Answer 16

Aromatic and aliphatic compounds

Question 17

Respiratory burst creates harsh chemistry within the body in order to kill pathogens. What is the reactant, product, and enzyme of this process?

Answer 17

Reactant: Hydrogen peroxide
Product: Hypochlorus acid
Enzyme: Myeloperoxidase

Question 18

This is a substance that inhibits oxidation and is capable of counteracting the damaging effects of oxidation in body tissue.

Answer 18

Antioxidant

Question 19

This is an atom or molecule that has one or more unpaired electrons. It is very reactive.

Answer 19

Free radical

Question 20

What are three common radicals/reactive species?

Answer 20

Superoxide, Hydrogen peroxide, Hydroxyl

Question 21

This is the process by which electronically excited molecules are inactivated.

Answer 21

Quenching

Question 22

When free radicals are quenched, what happens to antioxidants?

Answer 22

They are oxidized

Question 23

This is the process by which the antioxidant’s reducing power is restored.

Answer 23

Regeneration

Question 24

When antioxidants are regenerated, they are being what?

Answer 24

Reduced

Question 25

What are some important enzymes that may quench free radicals?

Answer 25

- Superoxide Dismutase (Quenches superoxide) - Catalase (Quenches hydrogen peroxide) - Glutathione Peroxidase (Quenches hydrogen peroxide)

Question 26

Where does superoxide dismutase act?

Answer 26

- Extracellular - Cytoplasm - Mitochondria

Question 27

What is the function of superoxide dismutase?

Answer 27

- Eliminate superoxide | - Produce hydrogen peroxide

Question 28

What does superoxide dismutase require?

Answer 28

- Zinc - Copper - Manganese (mitochondria)

Question 29

Where does catalase act?

Answer 29

- Mostly in cell peroxisomes | - Smaller amounts in cytoplasm, mitochondria, and microsomes

Question 30

What is the function of catalase?

Answer 30

Eliminate hydrogen peroxide by turning it into water

Question 31

Where does glutathione peroxidase act?

Answer 31

Cytosol and mitochondria

Question 32

What is the function of glutathione peroxidase?

Answer 32

Turns hydrogen peroxide into water