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17 Cards in this Set
- Front
- Back
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1. Retinol
2. Retinal 3. Retinoic Acid |
3 forms of Vitamin A
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retinol binding protein
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carries retinol from the liver to cells
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vision chemistry
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the visual molecule is called rhodopsin; it's made of 2 parts (retinal- vit A, opsin- protein)- in the dark, retinal is bent and attached to opsin. A flash of light straightens the retinal and breaks it from the opsin; then an enzyme rebends and reattches the retinal
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night blindness
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slow recovery of vision in the dark after a bright flash of light
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-required for the development of epithelial and goblet cells
-required by the immune system -required for bone modeling -involved in the production of steroid and thyroid hormones |
other roles of Vitamin A
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xerophthalmia
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blindness due to damage to the cornea because of a vitamin A deficiency
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beta-carotene
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a vitamin A precursor in plants
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-occurs at 15,000 ug (micrograms)
-joint pain, headache, slow clotting time, dry skin, nausea, diarrhea, irritability, fatigue, insomnia, amennorhea, birth defects |
Vitamin A toxicity symptoms
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Accutane and Retin-A
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made from vitamin A; they thin the skin to reduce acne
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- liver
- dairy - some fruits and vegetables |
Vitamin A sources
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Vitamin D
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it can be made in the skin with cholesterol and sunlight; it elongates intestinal villi; it increases calcium absorption; it promotes bone mineralization; also it increases resistance to TB
-deficiency is called rickets (soft bones) -toxicity causes calcium deposits in the soft tissues (50 ug) -good sources: dairy, 15 minutes of sunlight several times a week |
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tocopherol
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the general name for the 4 forms of vitamin E
-good sources: oil, seeds, nuts, eggs, leafy green vegetables -toxicity occurs at 1,000 mg (symptoms: nausea, cramps, blurry vision, fatigue) -it is destroyed be heat |
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free radicals
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atoms or molecules with an unpaired electron and they are very reactive
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-it is an antioxidant for the lipid tissues of the body
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Vitamin E's main function
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-anemia
-loss of coordination -poor vision -cysts in the breasts |
Vitamin E deficiency symptoms
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Vitamin K
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-required by the liver to make clotting factors; also required to make bone proteins
- good sources: milk, leafy green vegetables, GI bacteria -deficiency causes bleeding and weakness -toxicity occurs at 100X the RDA (symptoms: jaundice, red blood cell hemolysis, brain damage) |
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Hemorrhagic disease of the newborn
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-excessive bleeding due to low vitamin K because the GI tract is sterile before birth and the baby produces low prothrombin amount to reduce blood clotting before birth
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