Vit & Min Part 2 Abridged

Front 1

Which antioxidant is most effective in rapidly eliminating hydroxyl radicals prior to initiation of oxidative damage?

Back 1

Vit C

Front 2

Which antioxidant is most effective in terminating chain-propagation reactions in cell membranes?

Back 2

Vit E

Front 3

Which TWO of the following are reactive oxygen species, but do not fit the definition of a free radical?

1. Hydrogen or lipid peroxide
2. Singlet oxygen
3. Peroxyl radical
4. Superoxide anion
5. Hydroxyl radical
   

Back 3

1. Hydrogen or lipid peroxide
2. Singlet Oxygen

Front 4

Respiratory burst refers to the use of which reactive oxygen species by white blood cells to destroy foreign microbes?

1. Superoxide
2. peroxyl
3. Hypochlorus acid
4. Hydroxyl radical

Back 4

1. superoxide

Front 5

Which of the following is NOT a source of hydrogen peroxide production in the human body?

1. Tissue ischemia after injury
2. Glutathione peroxidase activation
3. ELimination of superoxide radicals
4. Degredation of long-chain fatty acids

Back 5

2. glutathione peroxidase activation

Front 6

The Fenton reaction involves the production of hydroxyl radical by the interaction of hydrogen peroxide with _______________.

Back 6

Iron

Front 7

Which reactive species is considered a major initiator of lipid peroxidation in the body?

1. Hydroxyl radical
2. Superoxide
3. Singlet oxygen
4. Hydrogen peroxide
   

Back 7

1. Hydroxyl radical

Front 8

Which reactive lipid species is the result of a propagation reaction between oxygen and lipid carbon-centered radicals?

1. Lipid peroxides
2. Additional lipid carbon-centered radicals
3. lipid peroxyl radicals
4. lipid alkoxyl radicals

Back 8

3. Lipid Peroxyl radicals

Front 9

Which THREE of the following minerals are necessary to the optimal performance of superoxide dismutase (SOD) in human tissues?

1. Zn
   
2. Mg
3. Se
4. Cu
5. Fe

Back 9

Zn, Mg, Cu

Front 10

T/F: The reactive species scavenging function of vitamin C is limited to reducing radical species, it does not scavenge non-radical species.

Back 10

False

Front 11

What mineral is essential to the function of glutathione peroxidase?

Back 11

Sel

Front 12

What is the role of glutathione in the reaction between glutathione peroxidase and various peroxide species?

1. Electron acceptor
2. Hydrogen acceptor
3. Component of enzyme protein sequence
4. Hydrogen donor
   

Back 12

4. Hydrogen donor (reducing agent)

Front 13

Which reactive species is referred to as an "electronically excited" molecule, and is inactivated by a process called "quenching"?

Back 13

Singlet Oxygen

Front 14

Which B-vitamin functions as a coenzyme to regenerate oxidized glutathione?

Back 14

Niacin (B3)

*technically NADPH (B3) and FADH2 (B2)*

Front 15

Which of the following statements is TRUE?

1. In general, vitamin C is more effective in lipid environments, while vitamin E is more effective in aqueous environments.
2. Natural and synthetic vitamin C are chemically identical and there are no known differences in their biological activities or bioavailability.
3. An important distinction between the two fat-soluble antioxidants beta-carotene and vitamin E may be that beta-carotene functions more on the cell surface, while vitamin E functions more in the interior of a cell.
4. The amount of vitamin C intake has little effect on vitamin C absorption.
   

Back 15

2. Natural and synthetic Vit C are chemically identical and there's no known difference in their biological activities and availability

Front 16

Which of the following is the source of hydrogen atoms for the regeneration of ascorbic acid from dehydroascorbate?

1. Glutathione
2. NADPH
3. FADH
4. Coenzyme Q
   

Back 16

1. Glutathione

Front 17

Which of the following enzymes is required for the synthesis of vitamin C and not present in human biochemistry?

1. Gulonolactone oxidase
2. Lysyl hydroxylase
3. Dehydroascorbate reductase
4. Aldonolactonase
5. Ascorbyl palmitase
   

Back 17

1. Gulonolactone oxidase
   

Front 18

Which reaction is typical of the kind catalyzed by vitamin C?

Back 18

Hydroxylation

Front 19

Which of the following is a function of vitamin C in human biology?

1. Norepinephrine synthesis
2. Collagen synthesis
3. Carnitine synthesis
4. Serotonin synthesis
5. Cholesterol synthesis
   

Back 19

1. + 4. Norepinephrine And Serotonin synthesis
2. Collagen synthesis
3. Carnitine synthesis

Front 20

Which TWO minerals can be reduced by ascorbate, leading to increased capacity for generation of reactive oxygen species?

1. Zinc
2. Magnesium
3. Selenium
4. Iron
5. Copper
   

Back 20

1. Iron
2. Copper

Front 21

An intervention trial found that large doses of vitamin C reduced blood levels of which toxic metal?

Back 21

Lead

Front 22

The Tolerable Upper Intake Level for vitamin C was set to help reduce the risk of what side effect of vitamin C supplementation?

1. Kidney stones
2. Hemochromatosis
3. Gastrointestinal upset and diarrhea
4. Rebound scurvy
   

Back 22

3. Gastrointestinal upset and diarrhea

Front 23

Match the substance with the most appropriate storage characteristic. (Match the red term with blue answer- one extra answer)

Retinol, Carotenoids, Tocopherol

1. Stored in liver, adipose, and concentrated in specific tissues
   
2. Primarily stored in the liver
3. Primarily stored in adipose tissue
   

Back 23

1. Carotenoids
2. Retinol
3. Tocopherol

Front 24

Match the characteristics with the most appropriate substance. (Match the red term with blue answer- one extra answer)

Retinol, B-Carotine, Tocopherol

1. Most essential for differentiation of epithelial cells
2. Effective for inhibiting both LDL oxidation AND blood clot formation
3. Effective for both free radical quenching AND inhibiting neoplastic transformation
   

Back 24

1. Retinol
2. Tocopherol
3. B-carotine

Front 25

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

1. Hemolytic anemia
2. Keratinization
3. Xeropthalmia
4. Night blindness
5. Neuromuscular degeneration

Back 25

1. Vit E
2. Vit A
3. Vit A
4. Vit A
5. Vit E

Front 26

Where is the primary site for conversion of provitamin A to vitamin A in the human body?

Back 26

Intestinal mucosa

Front 27

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?

1. Amino acid conjugation
2. Protein hydrolysis
3. De-esterification
4. Micelle formation
   

Back 27

1. Amino acid conjugation
   

Front 28

Which substance does not belong to the family of carotenoids?

1. Lutein
2. Canthaxanthin
3. Lycopene
4. Alpha-carotene
5. Tocotrienol
   

Back 28

5. Tocotrienol

Front 29

T/F: Vitamin A in the form of retinoic acid supports the development of cells by influencing gene expression.

Back 29

True

Front 30

What is the most likely mechanism for the effect of vitamin A on the growth of epithelial tissue?

1. Increases production of growth factors
2. Increases numbers of receptors for growth factors
3. Interferes with growth inhibitors
   

Back 30

2. Increases numbers of receptors for growth factors

Front 31

Which mineral deficiency interferes with vitamin A metabolism?

Back 31

Zinc

Front 32

In which of the following conditions is plasma retinol NOT a good reflection of vitamin A status?

1. Stores of vitamin A are exhausted
2. Stores of vitamin A are filled to capacity
3. Stores of vitamin A are partially depleted
   

Back 32

3. Stores of vitamin A are partially depleted

Front 33

For which group are large doses of beta-carotene not likely to be safe?

Back 33

Smokers

Front 34

Which of the following is not a sign of vitamin A toxicity?

1. Headache
2. Liver damage
3. Elevated blood pressure
4. Skin irritations
5. Bone pain
   

Back 34

Elevated Blood pressure

Front 35

Which of the following foods is the richest source of dietary alpha-tocopherol?

1. Peanuts, one ounce
2. Soybean oil, 1 tablespoon
3. Spinach, 1 cup raw
4. Almonds, one ounce
5. Sunflower oil, 1 tablespoon
   

Back 35

4. Almonds, one ounce

Front 36

Tocopherol is distributed to the tissues through receptor-mediated uptake of which lipoprotein?

Back 36

LDL

Front 37

Regeneration of oxidized vitamin E requires three of the following cofactors:

1. NADPH
2. Reduced glutathione
3. Vitamin C
4. FADH
   

Back 37

1. 4NADPH
2. Reduced glutathione
3. Vitamin C
   

Front 38

The Tolerable Upper Intake Level was set for vitamin E to prevent _____________.

Back 38

Increased tendency for bleeding

Front 39

Match the vitamin with the correct enzyme or coenzyme function.

Riboflavin, Biotin, Thiamin, Niacin, Pantothenic acid

1. Carboxylases
   
2. Acyl carrier protein
   
3. TPP
   
4. NADP/NADPH
   
5. FMN/FMNH2
   

Back 39

1. Carboxylases - Biotin
   
2. Acyl carrier protein- Pantothenic acid
   
3. TPP - Thiamin
   
4. NADP/NADPH- Niacin
   
5. FMN/FMNH2- Riboflavin
   

Front 40

A thiamin deficiency disorder usually associated with alcoholism is known as ____________.

Back 40

Wernicke-Korsakoff Syndrome

Front 41

The essential roles of thiamin in the body include (Indicate all of the correct answers):

1. Synthesis of coenzyme A
2. Energy transformation
3. Synthesis of pentoses and NADPH
4. Membrane and nerve conduction
   

Back 41

2. Energy transformation

3. Synthesis of pentoses and NADPH

4. Memberane and nerve conduction

Front 42

Which of the following is the best source of riboflavin?

Back 42

Milk and milk products

Front 43

Which of the following is NOT a role of flavoproteins (FAD) in intermediary metabolism?

1. Synthesis of an active form of folate
2. Coenzyme for an oxidase
3. Synthesis of pentoses and NADPH
4. Glutathione reduction
   

Back 43

3. Synthesis of pentoses and NADPH

Front 44

Which of the following is NOT a role of NADPH?

1. Cholesterol and steroid hormone synthesis
   
2. Synthesis of precursors of DNA
   
3. Beta-oxidation of fatty acids
4. Oxidation of glutamate

Back 44

3. Beta-oxidation of fatty acids

Front 45

Which amino acids is a precursor to niacin?

Back 45

Tryptophan

Front 46

Side effects arising from using niacin in therapeutic amounts may include all of the following effects except which one.

1. Headaches
2. Increased uric acid levels
3. Increased blood pressure
4. Liver injury
5. Elevated plasma glucose
6. Heartburn
   

Back 46

3. Increased blood pressure

Front 47

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.

Back 47

True

Front 48

Synthesis of coenzyme A starts with the phosphorylation of which vitamin?

Back 48

Pantothenoic acid (B5)

Front 49

T/F: Subclinical biotin deficiency may develop in some pregnant women.

Back 49

True

Front 50

Match the B-vitamin or its derivative with the therapeutic use shown effective in some human studies.

Biotin, Riboflavin, Pantethine

1. Blood cholesterol lowering
   
2. Blood sugar lowering
   
3. Migraine headache prevention
   

Back 50

1. Pantethine (B5)
2. Biotin (B7)
3. Riboflavin (B2)

Front 51

The activity of erythrocyte glutathione reductase is useful for assessing the adequacy of which B vitamin?

Back 51

Riboflavin (B2/FAD)

*NADP?

Front 52

The activity of erythrocyte transketolase is useful for assessing the adequacy of which B vitamin?

Back 52

Thiamine (B1)

Front 53

Acetyl CoA carboxylase depends on which B vitamin to begin fatty acid synthesis?

Back 53

Biotin (B7)

Front 54

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)

1. Thiamin
2. Niacin
3. Biotin
4. Pantothenate
5. Riboflavin
   

Back 54

3. Biotin (B7)

4. Panthothenate (B5)

Front 55

Excretion of fluorescent orange yellow urine follows oral ingestion of which vitamin?

Back 55

Riboflavin (B2)

Front 56

The pyruvate dehydrogenase complex depends on all of the following vitamins for its function: (list 4)

Back 56

1. B1- Thiamine
2. B2- Riboflavin
3. B3- Niacin
4. B5- Pantethenate

Front 57

Which of the B-vitamins can be synthesized by intestinal bacteria?

Back 57

Biotin

Front 58

Match the biological function with the required nutrient:

Vitamin B6, Vitamin B12, Folic acid

1. Transamination
   
2. One-carbon metabolism
   
3. Conversion of methylmalonyl CoA to succinyl CoA
   
4. Decarboxylation
   

Back 58

1. Transamination - B6
2. One-carbon Metabolism - Folic acid
3. Conversion of methylmalonyl CoA to succinyl CoA - B12
4. Decarboxylation- B6
   

Front 59

Megaloblastic anemia is associated with a deficiency of which micronutrient(s)?

Back 59

B12 and Folic Acid

Front 60

Microcytic anemia is associated with a deficiency of which micronutrient(s)?

Back 60

B6 (PLP, pyridoxine)

Front 61

Xanthurenic acid excretion following ___________ loading is a functional test used for B6.

Back 61

Tryptophan

Front 62

Which one of the following is NOT a reaction involving the coenzyme form of B6 (PLP)?

1. Conversion of homocysteine into methionine
2. Serine synthesis
3. Synthesis of heme
4. Formation of GABA from glutamate
   

Back 62

1. Conversion of homocycteine into methionine

Front 63

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___.

Back 63

1. Protein
2. R protein and intrinsic factor
3. ileum

Front 64

Which mineral is a component of vitamin B12?

Back 64

Cobalt

Front 65

The primary site for storage of vitamin B12 in the body is ____________.

Back 65

liver

Front 66

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?

1. Formation of pteroic acid
   
2. Can synthesize glutamic acid
   
3. Can synthesize pteridine
   
4. Can synthesize PABA
   

Back 66

1. Cannot form pteroic acid
   

Front 67

What vitamin deficiency can result in a tissue deficiency of active folate?

Back 67

Vit B12

Front 68

Folate is vitally important for dividing cells during growth and cancer because of its essential role in the synthesis of _____.

Back 68

purines and pyrimidines

Front 69

In the enzyme methionine synthase, vitamin B12 acts by accepting a ___1__ group from __2___ and donating this group to ___3__ to form methionine.

Back 69

1. methyl
2. 5MTHF
3. Homocysteine

Front 70

Which vitamin appears to be able to diminish the actions of steroid hormones by interfering with receptor binding?

1. Vitamin B12
   
2. Vitamin B6
   
3. Folic acid
   
4. None of these vitamins has such an effect
   

Back 70

2. Vit B6

Front 71

The metabolism of amino acids involving formaldehyde transfer all depend on the involvement of what vitamin?

Back 71

Folic Acid

Front 72

Which of the following is TRUE?

1. Excess vitamin B6 can mask a B12 deficiency
2. Excess vitamin B12 can mask a folic acid deficiency
3. Excess folic acid can mask a B12 deficiency
4. Excess vitamin B12 can mask a B6 deficiency
   

Back 72

3. Excess folic acid can mask a B12 deficiency

Front 73

Which vitamin is more easily absorbed from supplements because the food form contains glutamic acid residues that must be removed by the digestive process?

Back 73

Folic Acid

Front 74

Which cofactors/vitamins are involved in the 3 pathways of homocysteine metabolism?

Back 74

BHMT: Betaine, Zn

Transmethylation via MS: Folic Acid, B12

Methylation via SAMe: Mg, B2, B3, B12

Front 75

A genetic polymorphism that decreases the activity of N5,N10 methylene tetrahydrofolate reductase has been identified. This would cause _____.

Back 75

Increased homocycteine concentrations

Front 76

Match the vitamin D-related substance with its description.

cholecalciferol, ergocalciferol, calcitriol, 7-dehydrocholesterol, calcidiol

1. Vitamin D2 present in some plants
   
2. Fully activated form of vitamin D
   
3. Vitamin D3 precursor present in skin
4. Vitamin D3 produced in the skin
5. Most abundant form of vitamin D in the blood

Back 76

1. ergocalciferol
2. calcitriol
   
3. 7-dehydrocholesterol
4. cholecalciferol
   
5. calcidiol
   

Front 77

Which two organs are essential for the normal hydroxylations that convert cholecalciferol into systemically-active vitamin D hormone?

Back 77

Liver and kidney

Front 78

The primary function of vitamin D is to regulate absorption and metabolism of which 2 minerals?

Back 78

Calcium and Phosphorus

Front 79

Which of the following is not a function of calcitriol in the intestine?

1. synthesis of calbindin
2. modulation of gene expression
3. activation of adenylate cyclase
4. induction of changes in brush border composition
   

Back 79

3. activation of adenylate cyclase

Front 80

What disorder is associated with insufficient serum calcium and phosphorus, and leads to defective bone mineralization with preservation of bone matrix?

Back 80

Osteomalacia

Front 81

Dosages in excess of 10,000 IU/day of vitamin D for several months can result in which TWO events?

1. hypercalcemia
2. nephrolithiasis
3. over production of endogenous cholecalciferol
4. osteomalacia
   

Back 81

1. hypercalcemia
2. nephrolithiasis

Front 82

In assessing the vitamin D status of an individual, which measure would you use?

Back 82

circulating 25-OH cholecalciferol

Front 83

Regarding vitamin K sources, which of the following is NOT true?

1. Menaquinones are synthesized by intestinal bacteria
   
2. Dietary vitamin K is primarily menaquinones
   
3. Menaquinones are found in animal foods
   
4. Menadione is not found in nature
   
5. Phylloquinone is found in plant foods
   

Back 83

2. Dietary vitamin K is primarily menaquinones

Front 84

For what type of enzyme does vitamin K act as a cofactor?

Back 84

carboxylase

Front 85

Vitamin-K dependent modification of proteins such as the clotting factors affects the binding of which mineral ion by those proteins?

Back 85

calcium ions

Front 86

Which TWO names refer to anticoagulants that antagonize vitamin K action?

1. Mephyton
2. Ibuprofen
3. Warfarin
4. Coumadin
   

Back 86

Warfarin and Coumadin

Front 87

Which TWO of the following depend upon vitamin K for their production?

1. osteocalcin
2. prostaglandin
3. F2-alpha
4. 7-dehydrocholesterol
5. calcitonin
6. matrix Gla protein
   

Back 87

osteocalcin

matrix Gla protein

Front 88

What blood disorders is associated with vitamin K deficiency?

Back 88

hemorrhagic disease

Front 89

Which one of the following methods for determining vitamin K status is most likely to reflect recent intake rather than tissue status?

1. prothrombin time
   
2. undercarboxylated osteocalcin
   
3. plasma phylloquinone
   
4. undercarboxylated prothrombin
   

Back 89

plasma phylloquinone