Free Radicals Flashcards
(23 cards)
deficiency in this impairs the ability of an erythrocyte to form NADPH resulting in hemolysis
glucose 6 phosphate dehydrogenase
generates superoxide radicals
cytochrome P450
not a free radical since it has no unpaired electrons, but is still a reactive oxygen species
hydrogen peroxide
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)
what 4 ways can hydrogen peroxide be made
- ascorbate by eliminating superoxide radicals
- enzyme xanthine oxidase
- enzyme amine oxidase
- diffuse through water and lipids and move through cells and tissues to cause damage
hydrogen radicals are also produced from a reaction between hydrogen peroxide and superoxide radicals (non-enzymatic)
haber-weiss reaction
________ fatty acids are more susceptible to oxidation because they have more double bonds
polyunsaturated
singlet molecular oxygen is when an oxygen’s unshared electrons absorbs an energetic photon reaction via
photochemical reaction
vitamin A,C,E and minerals such as selenium, zinc, copper, manganese, and iron eleminate
free radicals
what aids in elimination of superoxide radicals
ascorbate and superoxide radicals
what aids in elimination of hydrogen peroxide
ascorbate, glutathione peroxidase, catalase, and myeloperoxidase
to increase glutathione levels, patients must be supplemented with
N-acetylcysteine and alpha-lipoic acid
what aids in elimination of hydroxyl radicals
ascorbate, glutathione, dihydrolipoic acid, coenyzme Q
vitamin E elimination of lipid carbon and peroxyl radicals: _____ is most effective in its ability to donate hydrogen ataoms
alpha-tocopherol
carotenoids elimination of lipid carbon and peroxyl radicals: ___ is most efficient free radical scavenger compared to vitamin E
lycopene
_______ most effective of all the carotenoids in quenching singlet oxygen
lycopene
______ 100x more efficient than vitamin E at quenching singlet molecular oxygen
lycopene and beta-carotene
___ can act as a pro-oxidant in the absence of co-antioxidants such as vitamin c
alpha-tocopherol
what is used in vitamin E regeneration
ascorbate glutathione or ubiquinone
what is used in vitamin C regeneration
semidehydroascorbic acid or dehydroascrobate
NADH and dihydrolipoic acid
what is used in ubiquinol regeneration
ubisemiquinone (DHLA and thioredoxin)
what is used in glutathione regeneration
oxidized glutathione (DHLA)
excess antioxidant depletes ______ and prevents apoptotic death of cancerous cells
ROS concentrations
