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
