Oxidative protection

Question 1

What are free radicals?

Answer 1

any molecule containing one or more unpaired electrons

• chemically reactive and highly unstable

Question 2

Free radicals lead to what?

Answer 2

1. cell damage
2. cell death
3. fatigue
4. accelerated aging

Question 3

What are sources of free radicals?

Answer 3

1. endogenous ( metabolism)
2. Exogenous (pollution, smoking)

Question 4

What is superoxide?

Answer 4

precursor of most other reactive O2 species

Question 5

How does O2 become superoxide?

Answer 5

O2 accepts a single electron during metabolism

Question 6

What is oxidative stress?

Answer 6

imbalance between production of reactive species and antioxidant defense activity

Question 7

What are antioxidants?

Answer 7

A substance in food that significantly decreases the adverse effects or reactive species on normal physiological function

Question 8

What do antioxidants donate to stabalize free radical?

Answer 8

electron

Question 9

What is Vitamin E?

Answer 9

• Lipid soluble
• Antioxidant
• Protects other substances from oxidation by being oxidized itself

Question 10

What are good sources of Vitamin E?

Answer 10

– vegetable oils
– margarine
– nuts (e.g. almonds) and seeds
(e.g. sunflower seeds)
– whole grain products
– green and leafy vegetables

Question 11

What is Vitamin C?

Answer 11

• Water soluble
• antioxidant
• protects water-soluble substances and some fat-soluble compounds (e.g. Vitamins A and E)
  from oxidation by being oxidized itself

Question 12

What vitamin can regenerate oxidized molecules to their original active forms?

Answer 12

Vitamin C

Question 13

What are good sources of Vitamin C?

Answer 13

citrus fruits, red peppers, strawberries,
broccoli etc

Question 14

What is Vitamin A?

Answer 14

• Lipid soluble

Question 15

How many type of Vitamin A are there?

Answer 15

1. Retinol
2. Retinal
3. Retinoic acid

Question 16

What is a plant-derived Vitamin A precursor?

Answer 16

Beta-carotene

Question 17

What is beta-carotene?

Answer 17

Extremely effective antioxidant

deep orange pigments and dark green veggies

Question 18

Minerals acts as what to enzymes?

Answer 18

cofactors that convert free radical to less damaging substances

Question 19

What is superoxide dismutase?

Answer 19

Enzyme which converts free radical (superoxide, O2) to O2 and hydrogen peroxide

Question 20

How many forms of superoxide dismutase are there?

Answer 20

1. maganese
2. copper and zinc

Question 21

What is catalase?

Answer 21

Protect the cell from the toxic effects of hydrogen peroxide

Question 22

What does catalase contain?

Answer 22

four heme (iron) rings which pull electrons away from water bonds, causing it to disassociate

Question 23

What are iron sufficent foods?

Answer 23

red meats, fish, poultry, shellfish, eggs,
legumes, dried fruit

Question 24

What is selenium?

Answer 24

works as part of
glutathione peroxidase
enzyme which converts
hydrogen peroxide into water and oxygen

Question 25

What are significant sources of selenium?

Answer 25

seafoods, meats, whole grains and vegetables