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89 Cards in this Set
- Front
- Back
Which antioxidant is most effective in rapidly eliminating hydroxyl radicals prior to initiation of oxidative damage? |
Vit C |
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Which antioxidant is most effective in terminating chain-propagation reactions in cell membranes? |
Vit E |
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Which TWO of the following are reactive oxygen species, but do not fit the definition of a free radical?
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Respiratory burst refers to the use of which reactive oxygen species by white blood cells to destroy foreign microbes?
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Which of the following is NOT a source of hydrogen peroxide production in the human body?
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2. glutathione peroxidase activation |
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The Fenton reaction involves the production of hydroxyl radical by the interaction of hydrogen peroxide with _______________. |
Iron |
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Which reactive species is considered a major initiator of lipid peroxidation in the body?
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1. Hydroxyl radical |
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Which reactive lipid species is the result of a propagation reaction between oxygen and lipid carbon-centered radicals?
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3. Lipid Peroxyl radicals |
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Which THREE of the following minerals are necessary to the optimal performance of superoxide dismutase (SOD) in human tissues?
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Zn, Mg, Cu |
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T/F: The reactive species scavenging function of vitamin C is limited to reducing radical species, it does not scavenge non-radical species. |
False |
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What mineral is essential to the function of glutathione peroxidase? |
Sel |
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What is the role of glutathione in the reaction between glutathione peroxidase and various peroxide species?
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4. Hydrogen donor (reducing agent) |
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Which reactive species is referred to as an "electronically excited" molecule, and is inactivated by a process called "quenching"? |
Singlet Oxygen |
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Which B-vitamin functions as a coenzyme to regenerate oxidized glutathione? |
Niacin (B3) *technically NADPH (B3) and FADH2 (B2)* |
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Which of the following statements is TRUE?
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2. Natural and synthetic Vit C are chemically identical and there's no known difference in their biological activities and availability |
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Which of the following is the source of hydrogen atoms for the regeneration of ascorbic acid from dehydroascorbate?
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Which of the following enzymes is required for the synthesis of vitamin C and not present in human biochemistry?
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Which reaction is typical of the kind catalyzed by vitamin C? |
Hydroxylation |
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Which of the following is a function of vitamin C in human biology?
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Which TWO minerals can be reduced by ascorbate, leading to increased capacity for generation of reactive oxygen species?
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An intervention trial found that large doses of vitamin C reduced blood levels of which toxic metal? |
Lead |
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The Tolerable Upper Intake Level for vitamin C was set to help reduce the risk of what side effect of vitamin C supplementation?
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3. Gastrointestinal upset and diarrhea |
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Match the substance with the most appropriate storage characteristic. (Match the red term with blue answer- one extra answer) Retinol, Carotenoids, Tocopherol
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Match the characteristics with the most appropriate substance. (Match the red term with blue answer- one extra answer) Retinol, B-Carotine, Tocopherol
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Match the function or deficiency symptom with the correct vitamin. (Match one of the red term with blue answer- one extra answer) Vit A, Vit E
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Where is the primary site for conversion of provitamin A to vitamin A in the human body? |
Intestinal mucosa |
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Three of the following digestive steps are required for normal absorption of vitamin A to occur in the gastrointestinal tract. Which one is not required?
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Which substance does not belong to the family of carotenoids?
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5. Tocotrienol |
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T/F: Vitamin A in the form of retinoic acid supports the development of cells by influencing gene expression. |
True |
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What is the most likely mechanism for the effect of vitamin A on the growth of epithelial tissue?
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2. Increases numbers of receptors for growth factors |
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Which mineral deficiency interferes with vitamin A metabolism? |
Zinc |
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In which of the following conditions is plasma retinol NOT a good reflection of vitamin A status?
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3. Stores of vitamin A are partially depleted |
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For which group are large doses of beta-carotene not likely to be safe? |
Smokers |
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Which of the following is not a sign of vitamin A toxicity?
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Elevated Blood pressure |
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Which of the following foods is the richest source of dietary alpha-tocopherol?
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4. Almonds, one ounce |
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Tocopherol is distributed to the tissues through receptor-mediated uptake of which lipoprotein?
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LDL |
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Regeneration of oxidized vitamin E requires three of the following cofactors:
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The Tolerable Upper Intake Level was set for vitamin E to prevent _____________.
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Increased tendency for bleeding |
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Match the vitamin with the correct enzyme or coenzyme function.
Riboflavin, Biotin, Thiamin, Niacin, Pantothenic acid
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A thiamin deficiency disorder usually associated with alcoholism is known as ____________. |
Wernicke-Korsakoff Syndrome |
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The essential roles of thiamin in the body include (Indicate all of the correct answers):
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2. Energy transformation 3. Synthesis of pentoses and NADPH 4. Memberane and nerve conduction |
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Which of the following is the best source of riboflavin? |
Milk and milk products |
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Which of the following is NOT a role of flavoproteins (FAD) in intermediary metabolism?
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3. Synthesis of pentoses and NADPH |
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Which of the following is NOT a role of NADPH?
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3. Beta-oxidation of fatty acids |
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Which amino acids is a precursor to niacin? |
Tryptophan |
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Side effects arising from using niacin in therapeutic amounts may include all of the following effects except which one.
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3. Increased blood pressure |
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T/F: Large doses of vitamin B3 as nicotinamide (niacinamide) do not possess the hypocholesterolemic effects of nicotinic acid (niacin), but also do not appear to have as high a potential for toxicity. |
True |
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Synthesis of coenzyme A starts with the phosphorylation of which vitamin?
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Pantothenoic acid (B5) |
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T/F: Subclinical biotin deficiency may develop in some pregnant women. |
True |
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Match the B-vitamin or its derivative with the therapeutic use shown effective in some human studies. Biotin, Riboflavin, Pantethine
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The activity of erythrocyte glutathione reductase is useful for assessing the adequacy of which B vitamin?
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Riboflavin (B2/FAD) *NADP? |
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The activity of erythrocyte transketolase is useful for assessing the adequacy of which B vitamin? |
Thiamine (B1) |
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Acetyl CoA carboxylase depends on which B vitamin to begin fatty acid synthesis? |
Biotin (B7) |
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Which vitamins use the AI recommendation for adult recommendations because there is insufficient available data to establish an RDA? (Indicate all of the correct answers)
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3. Biotin (B7) 4. Panthothenate (B5) |
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Excretion of fluorescent orange yellow urine follows oral ingestion of which vitamin? |
Riboflavin (B2) |
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The pyruvate dehydrogenase complex depends on all of the following vitamins for its function: (list 4) |
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Which of the B-vitamins can be synthesized by intestinal bacteria? |
Biotin |
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Match the biological function with the required nutrient: Vitamin B6, Vitamin B12, Folic acid
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Megaloblastic anemia is associated with a deficiency of which micronutrient(s)? |
B12 and Folic Acid |
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Microcytic anemia is associated with a deficiency of which micronutrient(s)?
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B6 (PLP, pyridoxine) |
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Xanthurenic acid excretion following ___________ loading is a functional test used for B6. |
Tryptophan |
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Which one of the following is NOT a reaction involving the coenzyme form of B6 (PLP)?
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1. Conversion of homocycteine into methionine |
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The normal digestion and absorption of cobalamin requires adequate ___1___ digestion in the stomach; the presence of 2 non-enzymatic proteins: __2___; and a receptor located in the __3___. |
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Which mineral is a component of vitamin B12? |
Cobalt |
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The primary site for storage of vitamin B12 in the body is ____________. |
liver |
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Mammals are unable to synthesize folic acid, even though they can accomplish several of the necessary steps. Which one of the following steps CANNOT be accomplished by mammals?
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What vitamin deficiency can result in a tissue deficiency of active folate?
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Vit B12 |
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Folate is vitally important for dividing cells during growth and cancer because of its essential role in the synthesis of _____. |
purines and pyrimidines |
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In the enzyme methionine synthase, vitamin B12 acts by accepting a ___1__ group from __2___ and donating this group to ___3__ to form methionine. |
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Which vitamin appears to be able to diminish the actions of steroid hormones by interfering with receptor binding?
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2. Vit B6 |
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The metabolism of amino acids involving formaldehyde transfer all depend on the involvement of what vitamin? |
Folic Acid |
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Which of the following is TRUE?
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3. Excess folic acid can mask a B12 deficiency |
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Which vitamin is more easily absorbed from supplements because the food form contains glutamic acid residues that must be removed by the digestive process? |
Folic Acid |
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Which cofactors/vitamins are involved in the 3 pathways of homocysteine metabolism? |
BHMT: Betaine, Zn Transmethylation via MS: Folic Acid, B12 Methylation via SAMe: Mg, B2, B3, B12 |
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A genetic polymorphism that decreases the activity of N5,N10 methylene tetrahydrofolate reductase has been identified. This would cause _____. |
Increased homocycteine concentrations |
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Match the vitamin D-related substance with its description.
cholecalciferol, ergocalciferol, calcitriol, 7-dehydrocholesterol, calcidiol
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Which two organs are essential for the normal hydroxylations that convert cholecalciferol into systemically-active vitamin D hormone? |
Liver and kidney |
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The primary function of vitamin D is to regulate absorption and metabolism of which 2 minerals? |
Calcium and Phosphorus |
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Which of the following is not a function of calcitriol in the intestine?
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3. activation of adenylate cyclase |
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What disorder is associated with insufficient serum calcium and phosphorus, and leads to defective bone mineralization with preservation of bone matrix? |
Osteomalacia |
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Dosages in excess of 10,000 IU/day of vitamin D for several months can result in which TWO events?
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In assessing the vitamin D status of an individual, which measure would you use? |
circulating 25-OH cholecalciferol |
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Regarding vitamin K sources, which of the following is NOT true?
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2. Dietary vitamin K is primarily menaquinones |
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For what type of enzyme does vitamin K act as a cofactor? |
carboxylase |
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Vitamin-K dependent modification of proteins such as the clotting factors affects the binding of which mineral ion by those proteins? |
calcium ions |
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Which TWO names refer to anticoagulants that antagonize vitamin K action?
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Warfarin and Coumadin |
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Which TWO of the following depend upon vitamin K for their production?
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osteocalcin matrix Gla protein |
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What blood disorders is associated with vitamin K deficiency? |
hemorrhagic disease |
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Which one of the following methods for determining vitamin K status is most likely to reflect recent intake rather than tissue status?
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plasma phylloquinone |