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 (B)</p> Signup and view all the answers

What is the primary action of an oxidant?

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

What is the role of an antioxidant in oxidation reactions?

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

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

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

What is the impact of radical species on DNA?

<p>Causing DNA mutations (C)</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 (D)</p> Signup and view all the answers

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

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

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

<p>Dehydroascorbic acid (C)</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 (D)</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 (C)</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 (D)</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 (C)</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 (A)</p> Signup and view all the answers

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

<p>Adrenal glands (A)</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 (D)</p> Signup and view all the answers

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

<p>Passive transport absorption decreases (A)</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 (D)</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 (A)</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 (A)</p> Signup and view all the answers

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

<p>300 mg (B)</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 (B)</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 (D)</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 (C)</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 (B)</p> Signup and view all the answers

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

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

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

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

Which species can synthesize vitamin C, unlike humans?

<p>Most species (C)</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 (D)</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 (A)</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 (A)</p> Signup and view all the answers

Which form of vitamin E is mostly found in humans?

<p>Alpha-tocophorol (C)</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 (D)</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 (D)</p> Signup and view all the answers

What is the primary route of vitamin E excretion?

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

What is the primary symptom of vitamin E deficiency?

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

What is the primary source of vitamin E in food?

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

What is the primary concern regarding vitamin E toxicity?

<p>Hemorrhagic stroke at high doses (C)</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 (B)</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 (B)</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 (B)</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 (A)</p> Signup and view all the answers

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

<p>Selenocysteine (B)</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 (A)</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 (D)</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 (B)</p> Signup and view all the answers

Which symptom is linked to selenium deficiency?

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

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

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

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

<p>Urine (C)</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 (C)</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 (B)</p> Signup and view all the answers

How is preformed Vitamin A absorbed in the small intestine?

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

What is the efficiency of absorption for preformed Vitamin A?

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

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

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

Where is retinol stored in the body?

<p>Liver (C)</p> Signup and view all the answers

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

<p>Liver (D)</p> Signup and view all the answers

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

<p>Intestines (C)</p> Signup and view all the answers

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

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

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

<p>Zinc (D)</p> Signup and view all the answers

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

<p>Ethanol (A)</p> Signup and view all the answers

What are the symptoms of vitamin A toxicity?

<p>Nausea, vomiting, headache, vertigo (A)</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 (D)</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 (B)</p> Signup and view all the answers

What are the symptoms of Vitamin A toxicity?

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

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

<p>900 μg/day (D)</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 (A)</p> Signup and view all the answers

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

<p>Menaquinone (D)</p> Signup and view all the answers

Which food source contributes significant amounts of vitamin K?

<p>Spinach (C)</p> Signup and view all the answers

What is the primary function of vitamin K?

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

Where is Phylloquinone absorbed in the body?

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

What is the AI for women for vitamin K?

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

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

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

What inhibits vitamin K absorption?

<p>Antibiotics (B)</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 (D)</p> Signup and view all the answers

Where does vitamin K toxicity primarily occur?

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

What is the primary symptom of vitamin K deficiency?

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

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

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

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

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

What is the primary symptom of vitamin K deficiency?

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

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

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

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

<p>Osteoporosis (A)</p> Signup and view all the answers

Why are newborns given a vitamin K injection at birth?

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

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

<p>10% (B)</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 (C)</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 (A)</p> Signup and view all the answers

Where is the majority of body iron found?

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

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

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

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

<p>Legumes (A)</p> Signup and view all the answers

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

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

Which factor influences the iron content in food?

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

What is the primary plasma protein carrier for iron?

<p>Transferrin (D)</p> Signup and view all the answers

What is the most common cause of anemia?

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

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

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

What is the primary symptom of iron deficiency?

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

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

<p>Feces (C)</p> Signup and view all the answers

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

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

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

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

What is the primary symptom of iron toxicity in children?

<p>Lethargy (A)</p> Signup and view all the answers

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

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

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

<p>Menstruation (B)</p> Signup and view all the answers

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

<p>Non-heme iron (B)</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 (D)</p> Signup and view all the answers

What is the primary symptom of iron deficiency?

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

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

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

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

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

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

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

What is the primary function of antioxidants in the body?

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

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

<p>Tocopherols (B)</p> Signup and view all the answers

What is the primary symptom of iron toxicity in children?

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

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