Chapter 8: antioxidant function

Question 1

what happens when oxidation and reduction are not paired?

Answer 1

an atom with an unpaired electron (free radical)

Question 2

what are some sources of free radical production?

Answer 2

asbestos, tobacco use, industrial chemicals, immune system, pollution, UV light, radiation, and excessive exercise

Question 3

and oxidized LDL is more likely to do what?

Answer 3

become part of plaque

Question 4

damage to what 4 things by free radicals contributes to oxidative stress?

Answer 4

cell membrane, proteins, LDL, and DNA

Question 5

oxidative stress can results in what diseases?

Answer 5

cancer, CVD, Alzheimer’s, arthritis, cataracts, type 2 diabetes, and Parkinson’s

Question 6

what controls free radical formation?

Answer 6

antioxidants

Question 7

what are the three ways the antioxidant enzyme system gets rid of free radicals?

Answer 7

breaks down oxidized fatty acids, makes more antioxidant vitamins available, and converts free radicals to less damaging substances

Question 8

what reactivates vitamin E?

Answer 8

vitamin C

Question 9

what reactivates vitamin C?

Answer 9

antioxidant enzyme system

Question 10

tocopherols

Answer 10

vitamin E added as a preservative

Question 11

main function of vitamin E

Answer 11

antioxidant in adipose tissue and cell membranes

Question 12

what does vitamin E protect?

Answer 12

poly-unsaturated fats and LDLs

Question 13

how does the body get rid of oxidized vitamin E?

Answer 13

excreted or reduced

Question 14

sources of vitamin E

Answer 14

vegetable oils, nuts, sunflower seeds, wheat germ, soybeans

Question 15

what are the risks of consuming too much vitamin E?

Answer 15

increases risk for heart failure, and can interfere with anticoagulant medications

Question 16

are there any risks with consuming too little vitamin E? why?

Answer 16

vitamin E deficiencies are uncommon because vitamin is a fat-soluble vitamin that is stored in the body

Question 17

what are the functions of vitamin C?

Answer 17

antioxidant, enhances absorption of iron, enhances the immune system

Question 18

what does vitamin C help synthesize? why is this important?

Answer 18

collagen (protein in connective tissue) -> important in wound healing

Question 19

smokers need an extra daily intake of what vitamin?

Answer 19

vitamin C

Question 20

vitamin C sources?

Answer 20

bell peppers, strawberries, pineapple, oranges, kiwi

Question 21

what can excess vitamin C intake do to people with hemachromatosis?

Answer 21

iron toxicity

Question 22

what can excess vitamin C intake do to people with kidney disease?

Answer 22

kidney stone formation

Question 23

what can a chronic intake of >2000 mg a day of vitamin C result in?

Answer 23

nausea, diarrhea, nosebleeds, abdominal cramps

Question 24

vitamin C deficiency may result in? symptoms?

Answer 24

scurvy (bleeding gums, loose teeth, wounds that fail to heal, bone pain, diarrhea, weakness, depression)

Question 25

selenium is an example of what? what are its functions?

Answer 25

trace mineral; production of thyroid hormone, antioxidant, and neutralizes peroxide molecules

Question 26

sources of selenium

Answer 26

brazil nuts, turkey giblets, halibut, tuna

Question 27

beta-carotene is an example of what?

Answer 27

carotenoid & provitamin; inactive precursor of retinol (vitamin A)

Question 28

functions of beta-carotene

Answer 28

relatively weak antioxidant, effective against oxidation in cell membranes and LDLs

Question 29

functions of carotenoids

Answer 29

enhance immune system, protect skin from damage by UV light, protect eyes from damage

Question 30

too much beta-carotene may result in?

Answer 30

skin turning yellow or orange, not toxic

Question 31

source of beta-carotene?

Answer 31

canned pumpkin, sweet potato, spinach, kale, carrots

Question 32

where is vitamin A stored?

Answer 32

liver, adipose tissue, kidneys and lungs

Question 33

functions of vitamin A

Answer 33

contributes to cell differentiation, reproduction and bone growth, essential to sight, may act as antioxidant

Question 34

rhodopsin

Answer 34

protein in retina part of rod cells, reacts to changes in light brightness (vitamin A is a component)

Question 35

iodopsin

Answer 35

part of cone cells, allows different colors to be seen (vitamin A is a component)

Question 36

too much vitamin A may lead to?

Answer 36

birth defects and permanent damage to the liver and eyes

Question 37

too little vitamin A may result in?

Answer 37

night blindness, irreversible blindness

Question 38

what vitamin does polar bear liver have a fatal dose of?

Answer 38

vitamin A

Question 39

what fraction of cancer deaths are related to nutrition and lifestyle?

Answer 39

1/3

Question 40

how does obesity affect cancer risk?

Answer 40

obesity increases cancer risk and recurrence

Question 41

what does excess body weight as an adolescent potentially put you at risk for?

Answer 41

cancer as an adult

Question 42

what are the three steps of carcinogenesis?

Answer 42

initiation, promotion, and progression

Question 43

initiation

Answer 43

a cell's DNA is damaged & mutated by a carcinogen, may remain at this step for years

Question 44

promotion

Answer 44

altered cell repeatedly divides, promoter agent activates oncogenes and tumor suppressor genes deactivated (promotes cell division & disrupts apoptosis)

Question 45

apoptosis

Answer 45

programmed cell death

Question 46

progression

Answer 46

cells grow out of control, tumor forms, metastasis

Question 47

nutrition-related factors that increase cancer risk

Answer 47

obesity, red/processed meats, salted & salt-preserved foods, high-calcium diets, alcohol, low level of physical activity

Question 48

nutrition-related factors that decrease cancer risk

Answer 48

fruits and nonstarchy vegetables, carotenoid-containing foods, tomato products, allium vegetables (onion, garlic), vitamin-C containing foods, folate-containing foods, fiber-containing foods, milk and calcium supplements, high level of physical activity, omega-3 fatty acids, limit soy w breast cancer

Question 49

how do omega-3 fatty acids decrease cancer risk?

Answer 49

decrease inflammation, cell proliferation, angiogenesis increase apoptosis

Question 50

angiogenesis

Answer 50

creating new blood vessels (to supply existing cancer cells with nutrients and oxygen)

Question 51

what are some nutritional recommendations for someone who is getting treatment for cancer?

Answer 51

several small snacks throughout the day, favorite foods @ any time of day, eat every few hours (don't wait until you feel hungry), biggest meal when hungriest, exercise lightly/walk to increase appetite before a meal