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Flashcards in 560C Vit and Min Deck (339)
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91

Match the substance with the most appropriate storage characteristic.
Retinol, Carotenoids, Tocopherol

Primarily stored in the liver
Primarily stored in muscle
Primarily stored in adipose tissue

Carotenoids - Primarily stored in adipose tissue
Retinol - liver
Tocopherol - adipose tissue

92

Match the characteristics with the most appropriate substance.

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

1. Retinol
2. Tocopherol
3. B-carotine

93

Which nutrient deficincy causes:
- Keratinization
- Xeropthalmia
- Night blindness

Vitamin A

94

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

Intestinal mucosa

95

Three of the following digestive steps are required for normal absorption of vitamin A to occur in the gastrointestinal tract.


2. Protein hydrolysis
3. De-esterification
4. Micelle formation

96

What 4 substances belong to the family of carotenoids?


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

97

What is the form of vitamin A attached to the protein opsin in a molecule of rhodopsin?

4. 11-cis retinal

98

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

TRUE

99

Why is retinoic acid considered a hormone?

3. It has receptors on the nucleus and causes a change in protein synthesis.

100

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

2. Increases numbers of receptors for growth factors

101

Which mineral deficiency interferes with vitamin A metabolism?

Zinc

102

What two conditions is plasma retinol a good reflection of vitamin A status?

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

103

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

Smokers

104

The upper limit for a safe amount of vitamin A has been suggested to be 3000 micrograms per day. How much would this be in International Units?

10,000 IU
Vitamin A: 1 IU is the biological equivalent of 0.3 mcg retinol, or of 0.6 mcg beta-carotene.

105

What are 4 signs of vitamin A toxicity?

1. Headache
2. Liver damage
4. Skin irritations
5. Bone pain

106

How many vitamers of vitamin E are there?

8 vitamers, including tocopherols and tocotienols

107

Alpha-tocopherol has the greatest vitamin E activity in the human body due to a selective preference for this specific vitamer in what part of vitamin E processing?

Hepatic cell production of VLDL

108

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

4. Almonds, one ounce

109

The latest RDA for vitamin E is expressed in milligrams of RRR-alpha-tocopherol, but most people are more familiar with the older International Units of measurement. What is the adult RDA for vitamin E in International Units if the value is 15 mg of RRR-alpha-tocopherol?

22.38 IU
Vitamin E: 1 IU is the biological equivalent of 0.67 mg d-alpha-tocopherol, or 0.9 mg of dl-alpha-tocopherol.

110

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

LDL

111

Regeneration of oxidized vitamin E requires three of the following cofactors

1. NADPH
2. Reduced glutathione
3. Vitamin C

112

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

Increased tendency for bleeding

113

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

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

114

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

Wernicke-Korsakoff Syndrome

115

The essential roles of thiamine in the body include: (3)


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

116

What is the best, common, source of riboflavin?

Milk and milk products

117

Name 3 roles of flavoproteins in intermediary metabolism?

1. Synthesis of an active form of folate
2. Coenzyme for an oxidase
4. Glutathione reduction

118

Name 3 roles of NADPH?

1. Cholesterol and steroid hormone synthesis
2. Synthesis of precursors of DNA
4. Oxidation of glutamate

119

Which amino acid is a precursor to niacin?

Tryptophan

120

Side effects arising from using niacin in therapeutic amounts may include (5)

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