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Flashcards in Free Radicals Deck (23)
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1

deficiency in this impairs the ability of an erythrocyte to form NADPH resulting in hemolysis

glucose 6 phosphate dehydrogenase

2

generates superoxide radicals

cytochrome P450

3

not a free radical since it has no unpaired electrons, but is still a reactive oxygen species

hydrogen peroxide

4

what are the 3 isoenzymes of superoxide dismutase (SOD)

1 and 2. extracellular and cytosolic SOD (require zinc an copper cofactors)
3. mitochondrial SOD (require manganese cofactor)

5

what 4 ways can hydrogen peroxide be made

1. ascorbate by eliminating superoxide radicals
2. enzyme xanthine oxidase
3. enzyme amine oxidase
4. diffuse through water and lipids and move through cells and tissues to cause damage

6

hydrogen radicals are also produced from a reaction between hydrogen peroxide and superoxide radicals (non-enzymatic)

haber-weiss reaction

7

________ fatty acids are more susceptible to oxidation because they have more double bonds

polyunsaturated

8

singlet molecular oxygen is when an oxygen's unshared electrons absorbs an energetic photon reaction via

photochemical reaction

9

vitamin A,C,E and minerals such as selenium, zinc, copper, manganese, and iron eleminate

free radicals

10

what aids in elimination of superoxide radicals

ascorbate and superoxide radicals

11

what aids in elimination of hydrogen peroxide

ascorbate, glutathione peroxidase, catalase, and myeloperoxidase

12

to increase glutathione levels, patients must be supplemented with

N-acetylcysteine and alpha-lipoic acid

13

what aids in elimination of hydroxyl radicals

ascorbate, glutathione, dihydrolipoic acid, coenyzme Q

14

vitamin E elimination of lipid carbon and peroxyl radicals: _____ is most effective in its ability to donate hydrogen ataoms

alpha-tocopherol

15

carotenoids elimination of lipid carbon and peroxyl radicals: ___ is most efficient free radical scavenger compared to vitamin E

lycopene

16

_______ most effective of all the carotenoids in quenching singlet oxygen

lycopene

17

______ 100x more efficient than vitamin E at quenching singlet molecular oxygen

lycopene and beta-carotene

18

___ can act as a pro-oxidant in the absence of co-antioxidants such as vitamin c

alpha-tocopherol

19

what is used in vitamin E regeneration

ascorbate glutathione or ubiquinone

20

what is used in vitamin C regeneration

semidehydroascorbic acid or dehydroascrobate
(NADH and dihydrolipoic acid)

21

what is used in ubiquinol regeneration

ubisemiquinone (DHLA and thioredoxin)

22

what is used in glutathione regeneration

oxidized glutathione (DHLA)

23

excess antioxidant depletes ______ and prevents apoptotic death of cancerous cells

ROS concentrations