Oxidants
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Questions and Answers

What is the defining characteristic of a radical species?

  • Contain no orbital electrons
  • Contain only unpaired orbital electrons
  • Contain only paired orbital electrons
  • Contain one or more orbital electrons with unpaired spin states (correct)

    • What type of compound promotes oxidation?

  • Radical species
  • Oxidant
  • Pro-oxidant (correct)
  • Antioxidant

    • What is the primary action of radical species?

  • Seek and 'steal' electrons from other molecules (correct)
  • Act as stabilizers for other compounds
  • Remain inert in chemical reactions
  • Donate electrons to other molecules

    • What is the defining characteristic of a radical species?

    <p>It contains one or more orbital electrons with unpaired spin states</p> Signup and view all the answers

    What is the primary action of an oxidant?

    <p>Oxidizes other compounds</p> Signup and view all the answers

    What is the role of an antioxidant in oxidation reactions?

    <p>Inhibits/reverses oxidation</p> Signup and view all the answers

    What is the primary effect of radical species on cell proteins?

    <p>Causing damage to cell proteins</p> Signup and view all the answers

    Which condition is NOT associated with the potential roles of radical species mentioned in the text?

    <p>Common cold</p> Signup and view all the answers

    What is the impact of radical species on DNA?

    <p>Causing DNA mutations</p> Signup and view all the answers

    What is the primary function of antioxidants in the body?

    <p>Prevent oxidation by donating electrons to stabilize radical species</p> Signup and view all the answers

    Which of the following vitamins meets the definition of dietary antioxidants?

    <p>Vitamin C</p> Signup and view all the answers

    Why are carotenoids included in the discussion of antioxidants despite not meeting the definition of dietary antioxidants?

    <p>Because they influence oxidative processes</p> Signup and view all the answers

    Which of the following foods is NOT listed as a source of vitamin C in the text?

    <p>Apples</p> Signup and view all the answers

    What is the oxidized form of ascorbic acid referred to in the text?

    <p>Dehydroascorbic acid</p> Signup and view all the answers

    Why do smokers require more vitamin C according to the text?

    <p>Higher oxidative stress and metabolic turnover of vitamin C</p> Signup and view all the answers

    What is the primary function of vitamin C as an enzyme cofactor?

    <p>Regulating reactions requiring reduced metal ions and protein synthesis</p> Signup and view all the answers

    What is the impact of high concentration vitamin C intake on absorption?

    <p>Passive transport with less than 50% absorption</p> Signup and view all the answers

    What is the effect of time release dose compared to single dose on vitamin C absorption?

    <p>Higher net absorption</p> Signup and view all the answers

    What is the role of vitamin C in relation to radical species and antioxidants?

    <p>Scavenging radical species and regenerating other antioxidants</p> Signup and view all the answers

    What is the source of released vitamin C in reaction to stress?

    <p>Adrenal glands</p> Signup and view all the answers

    What is the primary role of vitamin C as an enzyme cofactor?

    <p>Assisting in collagen and connective tissue synthesis</p> Signup and view all the answers

    What is the impact of high concentration vitamin C intake on absorption?

    <p>Passive transport absorption decreases</p> Signup and view all the answers

    What is the key function of vitamin C's reducing power?

    <p>Acting as an effective antioxidant for scavenging radical species</p> Signup and view all the answers

    What is the impact of time release dose compared to a single dose on vitamin C absorption?

    <p>Higher net absorption with time release dose</p> Signup and view all the answers

    What is the role of released vitamin C in reaction to stress?

    <p>Exact role unclear, may relate to antioxidant function</p> Signup and view all the answers

    At what pool size do scurvy symptoms occur in the body?

    <p>300 mg</p> Signup and view all the answers

    What is the maximum body pool size of vitamin C in non-smokers per kg of body weight?

    <p>22 mg/kg</p> Signup and view all the answers

    What happens to the excess of water-soluble compounds like vitamin C?

    <p>It is excreted via urine</p> Signup and view all the answers

    What is the fate of large intake of water-soluble compounds like vitamin C in the body?

    <p>They are degraded in the intestine</p> Signup and view all the answers

    What is the similarity between the bioavailability of vitamin C from food and pharmaceutical forms?

    <p>It is the same</p> Signup and view all the answers

    What is a symptom of scurvy caused by vitamin C deficiency?

    <p>Inflamed, bleeding gums</p> Signup and view all the answers

    In which countries is scurvy rare, unless there is low fruit and vegetable consumption?

    <p>Developed countries</p> Signup and view all the answers

    Which species can synthesize vitamin C, unlike humans?

    <p>Most species</p> Signup and view all the answers

    What is the Recommended Dietary Allowance (RDA) of vitamin C for women 19 years and older?

    <p>75 mg</p> Signup and view all the answers

    What is the potential consequence of suddenly stopping a high dose of vitamin C intake?

    <p>Development of scurvy</p> Signup and view all the answers

    What is the Tolerable Upper Intake Level (UL) for vitamin C in adults aged 19 and older?

    <p>2000 mg/day</p> Signup and view all the answers

    Which form of vitamin E is mostly found in humans?

    <p>Alpha-tocophorol</p> Signup and view all the answers

    What is the primary concern regarding vitamin E's function in some in vivo conditions?

    <p>Pro-oxidative function</p> Signup and view all the answers

    What is the potential impact of vitamin E in protecting LDL from oxidation?

    <p>Decrease oxidative damage to LDL</p> Signup and view all the answers

    What is the primary route of vitamin E excretion?

    <p>Through feces</p> Signup and view all the answers

    What is the primary symptom of vitamin E deficiency?

    <p>Peripheral neuropathy</p> Signup and view all the answers

    What is the primary source of vitamin E in food?

    <p>Vegetable oils &amp; spreads</p> Signup and view all the answers

    What is the primary concern regarding vitamin E toxicity?

    <p>Hemorrhagic stroke at high doses</p> Signup and view all the answers

    What is the Recommended Dietary Allowance (RDA) of vitamin E for men aged 19-50 years?

    <p>15 mg/day alpha-tocopherol</p> Signup and view all the answers

    How is vitamin E bioavailability affected by pharmaceutical forms?

    <p>Reduced due to lack of fats required for chylomicron formation</p> Signup and view all the answers

    What is the primary fate of vitamin E in the body if there is low intestinal absorption?

    <p>Excreted through feces</p> Signup and view all the answers

    What is the Tolerable Upper Intake Level (UL) for vitamin E in adults aged 19 and older?

    <p>1000 mg/day of any form of supplementary alpha-tocopherol</p> Signup and view all the answers

    What is the biologically active form of selenium found in animal tissues?

    <p>Selenocysteine</p> Signup and view all the answers

    Which food source is NOT listed as a good source of selenium in the text?

    <p>Leafy greens</p> Signup and view all the answers

    How does food content of selenium vary depending on its source?

    <p>Depends on the soil content where the plant or animal was raised</p> Signup and view all the answers

    What is the UL (Tolerable Upper Intake Level) of selenium for both males and females?

    <p>400 mcg/day</p> Signup and view all the answers

    Which symptom is linked to selenium deficiency?

    <p>Muscular discomfort and weakness</p> Signup and view all the answers

    What is the AI (Adequate Intake) of selenium for infants?

    <p>15 mcg/day</p> Signup and view all the answers

    What is the primary route of selenium excretion from the body?

    <p>Urine</p> Signup and view all the answers

    What is the Recommended Dietary Allowance (RDA) of selenium for men aged 19-50 years?

    <p>55 mcg/day</p> Signup and view all the answers

    What is the primary function of Vitamin A in relation to men's health?

    <p>Supports sperm production</p> Signup and view all the answers

    How is preformed Vitamin A absorbed in the small intestine?

    <p>It is hydrolyzed to retinol</p> Signup and view all the answers

    What is the efficiency of absorption for preformed Vitamin A?

    <p>70-90%</p> Signup and view all the answers

    What is the retinol activity equivalency (RAE) ratio for beta-carotene from food?

    <p>12:1</p> Signup and view all the answers

    How can one calculate the amount of retinol that can be produced from dietary beta-carotene?

    <p>Divide mcg dietary beta-carotene by 12</p> Signup and view all the answers

    Where is retinol stored in the body?

    <p>Liver</p> Signup and view all the answers

    Which of the following foods is a good source of preformed Vitamin A?

    <p>Liver</p> Signup and view all the answers

    What is the assumed conversion site of carotenoids to retinol in the body?

    <p>Intestines</p> Signup and view all the answers

    Which factor is known to reduce the absorption of Vitamin A?

    <p>Intestinal infections</p> Signup and view all the answers

    What is required for protein synthesis and is essential for Vitamin A absorption?

    <p>Zinc</p> Signup and view all the answers

    Which substance competes with retinol for enzyme pathways in the body?

    <p>Ethanol</p> Signup and view all the answers

    What are the symptoms of vitamin A toxicity?

    <p>Nausea, vomiting, headache, vertigo</p> Signup and view all the answers

    Why is vitamin A toxicity from food unlikely in developed countries?

    <p>The body regulates the absorption of vitamin A from food</p> Signup and view all the answers

    How does excess vitamin A from supplements cause cell damage?

    <p>It saturates protein carriers leading to free vitamin A which causes cell damage</p> Signup and view all the answers

    What are the symptoms of Vitamin A toxicity?

    <p>Nausea, vomiting, headache, and blurred vision</p> Signup and view all the answers

    What is the Recommended Dietary Allowance (RDA) of Vitamin A for men?

    <p>900 μg/day</p> Signup and view all the answers

    What is the average Vitamin A intake for women aged 18 to 74 years?

    <p>1169 RAE (mcg)/day</p> Signup and view all the answers

    What is the primary form of vitamin K found in fish oils and meats?

    <p>Menaquinone</p> Signup and view all the answers

    Which food source contributes significant amounts of vitamin K?

    <p>Spinach</p> Signup and view all the answers

    What is the primary function of vitamin K?

    <p>Blood clotting</p> Signup and view all the answers

    Where is Phylloquinone absorbed in the body?

    <p>Jejunum &amp; ileum</p> Signup and view all the answers

    What is the AI for women for vitamin K?

    <p>90 mcg/day</p> Signup and view all the answers

    What is the primary cause of secondary vitamin K deficiency symptoms?

    <p>Impaired fat absorption</p> Signup and view all the answers

    What inhibits vitamin K absorption?

    <p>Antibiotics</p> Signup and view all the answers

    Why are newborns given a vitamin K injection at birth?

    <p>To last until gut microflora are developed</p> Signup and view all the answers

    Where does vitamin K toxicity primarily occur?

    <p>From excessive supplementation</p> Signup and view all the answers

    What is the primary symptom of vitamin K deficiency?

    <p>Bruising and hemorrhage</p> Signup and view all the answers

    What is the Adequate Intake (AI) of vitamin K for women?

    <p>90 mcg/day</p> Signup and view all the answers

    What is the primary cause of secondary vitamin K deficiency symptoms?

    <p>Impaired fat absorption</p> Signup and view all the answers

    What is the primary symptom of vitamin K deficiency?

    <p>Bruising and hemorrhage</p> Signup and view all the answers

    What is the source of observed vitamin K toxicity in infants?

    <p>Excessive supplementation</p> Signup and view all the answers

    What is the observed association of low vitamin K with chronic disease?

    <p>Osteoporosis</p> Signup and view all the answers

    Why are newborns given a vitamin K injection at birth?

    <p>To prevent blood clotting inhibition</p> Signup and view all the answers

    What is the approximate absorption rate of non-heme iron on average?

    <p>10%</p> Signup and view all the answers

    Which type of iron is only found in flesh foods such as meat, poultry, and fish?

    <p>Heme iron</p> Signup and view all the answers

    What is the primary factor that increases the absorption of non-heme iron?

    <p>Consumption of iron chelates like ascorbic acid</p> Signup and view all the answers

    Where is the majority of body iron found?

    <p>In hemoglobin</p> Signup and view all the answers

    What is the approximate absorption rate of heme iron on average?

    <p>10%</p> Signup and view all the answers

    Which food source contains the most iron per gram of content?

    <p>Legumes</p> Signup and view all the answers

    What is the primary form of iron in the cytochromes of oxidative phosphorylation?

    <p>Heme iron</p> Signup and view all the answers

    Which factor influences the iron content in food?

    <p>Food processing methods</p> Signup and view all the answers

    What is the primary plasma protein carrier for iron?

    <p>Transferrin</p> Signup and view all the answers

    What is the most common cause of anemia?

    <p>Iron deficiency</p> Signup and view all the answers

    What is the primary form of iron absorption inhibited by calcium and phosphorus?

    <p>Heme iron</p> Signup and view all the answers

    What is the primary symptom of iron deficiency?

    <p>Blue sclera</p> Signup and view all the answers

    What is the primary route of iron loss from the body?

    <p>Feces</p> Signup and view all the answers

    What is the primary factor contributing to increased non-heme iron absorption?

    <p>Ascorbic acid</p> Signup and view all the answers

    What is the primary contributor to iron stores in the body?

    <p>Dietary intake</p> Signup and view all the answers

    What is the primary cause of increased iron absorption in individuals with low iron stores?

    <p>Enhanced absorption efficiency</p> Signup and view all the answers

    What is the primary symptom of iron toxicity in children?

    <p>Lethargy</p> Signup and view all the answers

    What is the Recommended Dietary Allowance (RDA) of iron for premenopausal women?

    <p>18 mg/day</p> Signup and view all the answers

    What is the primary route of iron loss from the body?

    <p>Menstruation</p> Signup and view all the answers

    What is the primary form of iron absorption inhibited by calcium and phosphorus?

    <p>Non-heme iron</p> Signup and view all the answers

    What is the primary contributor to iron stores in the body?

    <p>Iron recycling from red blood cells</p> Signup and view all the answers

    What is the primary symptom of iron deficiency?

    <p>Impaired intellectual performance</p> Signup and view all the answers

    What is the Recommended Dietary Allowance (RDA) of iron for premenopausal women?

    <p>18 mg/day</p> Signup and view all the answers

    What is the primary effect of radical species on cell proteins?

    <p>Promotion of oxidation</p> Signup and view all the answers

    What is the primary form of iron in the cytochromes of oxidative phosphorylation?

    <p>Heme iron</p> Signup and view all the answers

    What is the primary function of antioxidants in the body?

    <p>Preventing oxidation reactions</p> Signup and view all the answers

    What is the primary form of vitamin E found in humans?

    <p>Tocopherols</p> Signup and view all the answers

    What is the primary symptom of iron toxicity in children?

    <p>Organ damage</p> Signup and view all the answers

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