E2 Pentose Phosphate Pathway

Question 1

What is the location of PPP?

Answer 1

cytosol/cytoplasm

Question 2

What is the main product of PPP?

Answer 2

NADPH

Question 3

What are the 3 other names for PPP?

Answer 3

A. hexose monophosphate pathway
B. hexose monophosphate shunt
C. phosphogluconate pathway

Question 4

Name the two phases of PPP.

Answer 4

1. oxidative

2. non-oxidative

Question 5

What is the key regulatory enzyme of PPP?

Answer 5

G-6-P DH

Question 6

T/F. ATP can be either created or consumed in PPP.

Answer 6

False; no ATP used/made

Question 7

Which PPP phase includes the interconversion of sugars?

Answer 7

non-oxidative

Question 8

Which PPP phase includes the production of NADPH?

Answer 8

oxidative

Question 9

In which cells does the PPP occur?

Answer 9

practically all

Question 10

Which enzyme(s) phosphorylate glucose?

Answer 10

hexokinase/glucokinase

Question 11

What cellular condition stimulates PPP?

Answer 11

low NADPH

Question 12

What is the main sugar in the non-oxidative phase of PPP?

Answer 12

Ribose-5-P

Question 13

Match the enzyme to the rxn.
A. G-6-P+NADP++H2O –> 6phosphoglucono-sigma-lactone
B. 6phosphoglucono-sigma-lactone –> 6-phosphogluconate
C. 6 phosphogluconate+NADP+ –> Ribose-5-phosphate + NADPH

1. lactonase
2. 6-phosphogluconate DH
3. transketolase
4. glucose-6-phosphate DH
5. transaldolase

Answer 13

A. 4
B. 1
C. 2

Question 14

Which rxn is the key rate limiting step in PPP? Is it reversible?

Answer 14

G-6-P + NADP+ + H2O –> 6 phosphoglucono-sigma-lactone; none are reversible

Question 15

How many NADPH are produced per 1 glucose-6-phosphate?

Answer 15

2

Question 16

What is used as an electron donor in detoxification?

Answer 16

NADPH

Question 17

Which rxn does NADPH not provide reducing power for? (pick two)
A. cholesterol synthesis
B. nucleotide synthesis
C. protein synthesis
D. respiratory bursts
E. antioxidant regeneration 
F. fatty acid synthesis
G. fatty acid breakdown 
H. detoxification

Answer 17

C. protein synthesis

G. protein breakdown

Question 18

Which detoxification system is used in the liver?

Answer 18

P450 monooxygenase system and/or cytochrome 450 monooxygenase system

Question 19

_____ and _____ are required to make toxins soluble.

Answer 19

Electrons, oxygen

Question 20

Name the process in which white blood cells take in more oxygen.

Answer 20

respiratory burst

Question 21

What is the location of the cytochrome P-450 monooxygenase system?

Answer 21

endoplasmic reticulum

Question 22

What is the fate of soluble toxins?

Answer 22

excrete in urine

Question 23

Where are reactive molecules and non-self (bacteria) sequestered?

Answer 23

in a vesicle

Question 24

In a respiratory burst, is NADPH used as an electron donor or acceptor?

Answer 24

donor

Question 25

What is used to produce reactive molecules in harsh chemistry?

Answer 25

O2 and electrons from NADPH

Question 26

Respiratory Burst Matching A. O2+NADPH --> O2- +NADP+ B. O2- --> H2O2 C. H2O2 --> HClO 1. lactonase 2. superoxide dismutase 3. transketolase 4. myeloperoxide 5. oxidase 6. G-6-P DH

Answer 26

A. 5 B. 2 C. 4

Question 27

What is the lettering for hypochlorous acid? Superoxide?

Answer 27

HClO, O2-

Question 28

_______ give electrons to free radicals to "quench" them.

Answer 28

antioxidants

Question 29

Proteins, phospholipids, and DNA are oxidized via _______.

Answer 29

free radicals

Question 30

_______ gives electrons to antioxidants.

Answer 30

NADPH

Question 31

Do free radicals have paired or unpaired electrons? Do they want to give or take electrons?

Answer 31

unpaired, take electrons

Question 32

Antioxidants Matching (multiple answers for each) A. superoxide B. hydrogen peroxide 1. reactive species 2. free radical 3. catalase 4. O2- 5. glutathione peroxide 6. superoxide dismutase

Answer 32

A. 2, 4, 6 | B. 1, 3, 5

Question 33

What are the 3 cofactors of superoxide dismutase?

Answer 33

zinc, copper, manganese

Question 34

What is the cofactor of catalase?

Answer 34

iron

Question 35

What is the cofactor of glutathione peroxide (GPX)?

Answer 35

selenium

Question 36

Name the location(s) of superoxide dismutase.

Answer 36

extracellular, cytoplasm, mitochondria

Question 37

What is the major location of catalase?

Answer 37

cell peroxisomes

Question 38

Name the location(s) of GPX.

Answer 38

cytosol, mitochondria

Question 39

What are the 2 functions of superoxide dismutase?

Answer 39

1. eliminate superoxide | 2. produce H2O2

Question 40

What is the main function of catalase and GPX?

Answer 40

eliminate H2O2

Question 41

T/F. Neutrophils have LOTS of catalase.

Answer 41

true

Question 42

What is the most significant antioxidant in the elimination of H2O2?

Answer 42

GPX

Question 43

What makes up the tripeptide glutathione?

Answer 43

glutamate-cysteine-glycine

Question 44

Glutathione Matching A. GSH B. GSSG 1. oxidized form 2. reduced form

Answer 44

A. 2 | B. 1

Question 45

Regerating glutathione requires electrons from ______.

Answer 45

NADPH

Question 46

What is the enzyme that facilitates GSSG ---> 2-GSH?

Answer 46

glutathione reductase

Question 47

What enzyme facilitates O2- ---> H2O?

Answer 47

superoxide dismutase

Question 48

What enzyme facilitates H2O ---> H2O + O2?

Answer 48

catalase

Question 49

What enzymes facilitates H2O ---> H2O?

Answer 49

GPX

Question 50

T/F. When antioxidants are regenerated, PPP is inhibited.

Answer 50

false; stimulates PPP

Question 51

Pentose Phosphate Pathway is ______ driven.

Answer 51

product

Question 52

Matching A. Ribose-5-Phosphate (C5) B. Glyceraldehyde-3-phosphate 1. transketolase 2. transaldolase

Answer 52

A. 1 | B. 2

Question 53

T/F. Ribose is NOT needed for DNA and RNA.

Answer 53

False

Question 54

What are options for reversible non-oxidative reactions?

Answer 54

build new cells, glycolysis, recycle sugars to G-6-P