Oxidative protection Flashcards
What are free radicals?
any molecule containing one or more unpaired electrons
- chemically reactive and highly unstable
Free radicals lead to what?
- cell damage
- cell death
- fatigue
- accelerated aging
What are sources of free radicals?
- endogenous ( metabolism)
- Exogenous (pollution, smoking)
What is superoxide?
precursor of most other reactive O2 species
How does O2 become superoxide?
O2 accepts a single electron during metabolism
What is oxidative stress?
imbalance between production of reactive species and antioxidant defense activity
What are antioxidants?
A substance in food that significantly decreases the adverse effects or reactive species on normal physiological function
What do antioxidants donate to stabalize free radical?
electron
What is Vitamin E?
- Lipid soluble
- Antioxidant
- Protects other substances from oxidation by being oxidized itself
What are good sources of Vitamin E?
– vegetable oils
– margarine
– nuts (e.g. almonds) and seeds
(e.g. sunflower seeds)
– whole grain products
– green and leafy vegetables
What is Vitamin C?
- Water soluble
- antioxidant
- protects water-soluble substances and some fat-soluble compounds (e.g. Vitamins A and E)
from oxidation by being oxidized itself
What vitamin can regenerate oxidized molecules to their original active forms?
Vitamin C
What are good sources of Vitamin C?
citrus fruits, red peppers, strawberries,
broccoli etc
What is Vitamin A?
- Lipid soluble
How many type of Vitamin A are there?
- Retinol
- Retinal
- Retinoic acid
What is a plant-derived Vitamin A precursor?
Beta-carotene
What is beta-carotene?
Extremely effective antioxidant
deep orange pigments and dark green veggies
Minerals acts as what to enzymes?
cofactors that convert free radical to less damaging substances
What is superoxide dismutase?
Enzyme which converts free radical (superoxide, O2) to O2 and hydrogen peroxide
How many forms of superoxide dismutase are there?
- maganese
- copper and zinc
What is catalase?
Protect the cell from the toxic effects of hydrogen peroxide
What does catalase contain?
four heme (iron) rings which pull electrons away from water bonds, causing it to disassociate
What are iron sufficent foods?
red meats, fish, poultry, shellfish, eggs,
legumes, dried fruit
What is selenium?
works as part of
glutathione peroxidase
enzyme which converts
hydrogen peroxide into water and oxygen
What are significant sources of selenium?
seafoods, meats, whole
grains and vegetables
