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73 Cards in this Set
- Front
- Back
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Diseases linked to oxidative damage
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cancers, heart disease, diabetes, arthritis, cataracts, kidney disease, alzheimer, parkinson, aging
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atom
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composed of nucleus and electrons
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nucleus
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positive charged center, made of neutrons and protons
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electrons
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negative charged particles that surround nucleus
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molecules
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composed of atoms
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oxidation
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a chemical reaction in which atoms lose electrons; leaves an odd number or unpaired electron
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reduction
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occurs when atoms gain an electron
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Stable atoms have...
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an even number of electrons (pairs) in the outer orbit
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Free radicals
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highly unstable atoms; free radicals cause damage to cell membranes, DNA; free radicals form within the phospholipid bilayers of cell membranes; damaged lipid molecules are unable to maintain the integrity of the cell membrane
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What causes free radicals to form?
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many metabolic processes: digestion and absorption of food, immune system fighting infections
Environmental factors: pollution, excess sunlight, toxic substances, tobacco smoke, abestos |
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How do antioxidants work?
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they stabilize free radicals and repair the damage they cause
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Antioxidant vitamins
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donate their their electrons or hydrogen molecules to free radicals to stabilize them and reduce oxidation damage
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Antioxidant minerals
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function within the enzyme systems that convert free radicals to less damaging substances that can be excreted
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Antioxidant enzymes
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protect cells from oxidative stress; make more vitamin antioxidants available to fight free radicals
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minerals that function as cofactors
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selenium, copper, iron, zinc, and manganese
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superoxide dismutase
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enzyme that converts free radicals to less damaging substances, such as hydrogen peroxide; copper, zinc, manganese
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catalase
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enzyme that removes hydrogen peroxide (called a Reactive Oxygen Species) from the body by converting it to water and oxygen; iron
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gluthathione peroxidase
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enzyme that also removes hydrogen peroxide from the body and stops the production of free radicals in lipids; selenium
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These minerals serve as cofactors in antioxidant enzymes
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copper, zinc, manganese= superoxide dismutase
iron= catalase selenium= glutathione peroxidase |
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Copper food sources
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whole grains, legumes, organ meats, cherries, dark chocolate, leafy green vegetable, nuts
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Zinc food sources
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meats, fish, dairy, legumes
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Manganese food sources
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pineapple, nuts, oatmeal, whole grains, legumes
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Iron food sources
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red meats, fortified cereals, legumes, spinach, sardines, clams
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Other compounds that help stabilize free radicals and prevent damage to cells and tissues
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beta-carotene, phytochemicals
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nutrients with antioxidant properties
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vit. E, C, A, and selenium
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Vitamin E
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fat soluble, absorbed with dietary fat; incorporated into the chylomicron to be transported to the liver; incorporated into lipoproteins; stored in adipose tissue (90%) and cell membranes; tocopherol is active form of vit. E
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RDA of vitamin E?
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15mg alpha-tocopherol per day
UL: 1000mg alpha-tocopherol per day (needs increase with higher intake of oils) |
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Functions of Vitamin E?
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protects lipids from free radicals: polyunsaturated fatty acids, cell membranes, and LDL from oxidization; normal nerve and muscle development; enhances immune system; promotes vit. A absorption if low
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Food sources of Vitamin E
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vegetable oils, nuts, seeds, wheat germ, soybeans, green leafy veggies
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Vitamin E is destroyed when...
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exposed to oxygen, metals, ultraviolet light, and heat
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Too much Vitamin E
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uncommon but high doses have been linked with heart disease and death; interacts with anticoagulants (aspirin and coumadin)> excessive bleeding
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Deficiency of Vitamin E
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survey>increased risk for cardiovascular disease; can result in erythrocyte hemolysis; symptoms: loss of muscle coordination and reflexes, impaired vision, speech, and movement; impaired immune function; associated with fat malabsorption
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Vitamin C
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water-soluble; must be consumed on a regular basis; synthesizes collagen (prevents scurvy), DNA, bile, neurotransmitters (seratonin), carnitine (transport long-chain fatty acids for energy production), hormones (thyroxine, epinephrine, steroids)
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more functions of Vitamin C
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antioxidant protects: LDL-cholesterol from oxidation, Lungs from ozone and cigarette damage, White blood cells; reduces formation of nitroamines, cancer-causing agent found in cured and processed meats; regenerates vitamin E by donating electrons; enhances iron absorption
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RDA of Vitamin C
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90mg/day for men, 75 mg/day for women; smokers need additional 35mg/day
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situations requiring more vitamin C
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healing from traumatic injury, surgery, burns, exposure to pollution
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Food sources of Vitamin C
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fruits, vegetables
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Vitamin C can be destroyed by...
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heat and oxygen
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Deficiency of Vitamin C?
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scurvy- most common deficiency disease> bleeding gums, loose teeth, weakness, wounds that fail to heal, depression; impaired ability to burn fat, impaired immunity, depression
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Who are at risk for a Vitamin C deficiency?
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people who eat few fruits and vegetables, or abuse alcohol and drugs
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Too much Vitamin C?
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extra is just secreted; consuming excess is not toxic; megadoses may cause nausea, diarrhea, nosebleeds, rebound scurvy
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Beta Carotene
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carotenoid, a classification of plant chemicals; precursor of retinol (vitamin A) which is its active form
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Functions of beta carotene
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antioxidant; effective against lipid oxidation in cell membranes; enhance immune system; protects skin from UV light damage; protect eyes from damage, preventing vision impairment
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RDA of beta carotene?
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not an essential nutrient, no RDA
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Food sources of beta carotene
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red, orange, yellow and deep green fruits and vegetables
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Too much beta carotene?
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not toxic; carotenosis or carotenodermia is harmless and reversible
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Not enough beta carotene?
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no deficiency symptoms
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Vitamin A
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fat soluble; excess is stored in the liver, adipose tissues, kidneys, and lungs
Active forms: retinol>retinal>retinoic acid |
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Functions of Vitamin A
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antioxidant, scavenges free radicals and protects LDL from oxidation; essential for proper vision; cell differentiation; sperm production; bone growth
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RDA of Vitamin A
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900mcg/day for men, 700 mcg/day for women
UL: 3000mcg/day of preformed vit A |
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Food sources of Vitamin A
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preformed- animal foods (liver, egg yolks, whole-fat dairy, fortified foods)
Plants high in beta carotene |
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Too much Vitamin A?
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highly toxic> birth defects, damage to liver and eyes, symptoms: loss of appetite, blurred vision, hair loss, skin disorders
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Deficiency of Vitamin A
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night blindness, xerophthalmia, hyperkeratosis, bitot's spots, blindness; impaired immunity and growth
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Selenium
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trace mineral needed in small amounts; varying amounts in soil; antioxidant, part of glutathione peroxidase enzyme (decreases free radicals sparing vit E); production of thyroxine, thyroid hormone (maintains basal metabolism and body temp)
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Sources of selenium
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organ meats, pork, seafood, buts, wheat, rice
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Too much selenium?
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toxicity from supplements> brittle hair, nails, skin rashes, vomiting, nausea, weakness, cirrhosis of liver
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Deficiency of selenium?
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associated with Keshan disease (heart diease), Kashin-Beck disease (deforming arthritis), impaired immunity
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phytochemicals
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naturally occuring chemicals in plants; may reduce risk for cancer, heart disease; include phytosetogen, lycopene, and flavenoids
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Food sources of phytochemicals
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whole grains, fruits, vegetables, legumes, nuts, garlic, soy, tea, coffee, red wine, cocoa
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Cancer
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a group of diseases characterized by cells growing out of control
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Primary steps of cancer development
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-initiation
-promotion -progression |
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Initiation of cancer
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a carcinogen causes a mutation int he DNA of a normal cell
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Promotion of cancer
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cell with mutation in DNA divides repeatedly
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Progression of cancer
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cancer cells invade surrounding tissues and spread to other sites in the body
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risk factors of cancer
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tobacco use, sun exposure, nutrition, environmental exposures, low levels of physical activity
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antioxidants reduce cancer risk by
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enhancing immune system; inhibits cancer cell growth; prevents oxidative damage to cells
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Tobacco use leads to many health problems such as...
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cancers, heart disease, bronchitis, emphysema, stroke, aging
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Cardiovascular disease (CVD)
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coronary heart disease, hypertension, atherosclerosis; >heart attack, stroke
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major risk factors for CVD
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smoking, hypertension, high blood levels of low density lipoprotein (LDL) cholesterol, obestiy, sedentary lifestyle, diet
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Antioxidants and CVD
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antioxidants in foods reduce damage to blood vessels by: scavenging free radicals, reducing low-grade inflammation, reducing blood coagulation, and clot formation
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Aging skin caused by...
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UV rays, and toxic chemicals
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Prevention of aging skin
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avoid sun exposure, cigarette smoke, eat antioxidants; vit A and E in skin creams
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Antioxidants play a role in eye health
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Macular degeneration: leading to blindness, deterioration of center portion of retina, marked by loss or distortion of central vision; cataract- damaged portion of eye's lens causing cloudy vision
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