The radius of the earths very nearly circular orbit around the sun is 1.5 * 1011 m. Find the magnitude of the earths (a) velocity, (b) angular velocity, and (c) centripetal acceleration as it travels around the sun. Assume a year of 365 days
DIT 125, Chapter 6 Vitamins 1 General Characteristics of Vitamins 1. Small, organic compounds. 2. Usually obtained from food. a. Synthesized by body b. Precursor compounds. 3. Essential to life. 4. Each has a specific function. 5. Regulate body processes. 6. Contain no kcalories. 7. Toxicity at mega doses: 10x RDA 8. No perfect food contains all vitamins. 9. Body can’t defect difference between synthetic and natural vitamin. 10. Classified as fat or water soluble. DIT 125, Chapter 6 Vitamins 2 Fat and Water Soluble Vitamins Fat soluble Water soluble Carried in fat Soluble in water A, D, E, K Thiamin, riboflavin, niacin, folate,B12, B6, biotin, pantothenic acid, vitamin C. Needed every three days. Needed daily Deficiencies develop Deficiencies develop slowly quickly Transported lymph. Stored Transported in blood. Not in the liver and body stored in the body adipose Excess toxic in small Excess usually not toxic. amounts (6-10x RDA) (> 10 x RDA) Have precursors or Generally do not have precursors. provitamins. DIT 125, Chapter 6 Vitamins 3 Vitamin A Most versatile of the fat soluble vitamins. Functions: 1. Promotes good night vi sion and normal vision. 2. Promotes cell differentiation. 3. Supports immune system. 4. Promotes growth and reproduction. Precursor: beta carotene 2001 Recommendations: RAE (Retinol Activity Equivalent) 1 mcg retinol = RAE 12 mcg beta carotene = RAE 24 mcg other carotene = RAE Deficiency: • Night blindness • Xerophthalmia Toxicity: As little as 5x the RDA Foods: Liver, fish liver oils, egg yolk, milk and butter. Rich yellow, deep orange fruits & vegetables. Fortified nonfat milk. DIT 125, Chapter 6 Vitamins 4 Vitamin D - Calciferol . Different from others, our body synthesizes. Not essential. 1. D3 = Synthesized from sunlight. 2. Provitamin D – animals Roles in the body. 1. Promotes bone mineralization. 2. Raises blood concentration of Calcium and phosphorus Deficiency: 1. rickets 2. osteomalcia Toxic: THE MOST TOXIC at 4-5x the DRI. Sources: Egg yolk, liver and fatty fish, fortified milk. Sunlight. DIT 125, Chapter 6 Vitamins 5 Vitamin E ( Tocopherol) Function: antioxidant 1. Protects PUFA 2. Protects Vitamin A 3. Protects RBC and brain 4. Protects lungs 5. Immune system Deficiency: Rare. • Neuromuscular dysfunction • Erythrocyte breakdown Toxicity: rare. Upper limit: 1000 mg DRI RDA) 2000: 15α TE mg for adults Food: Vegetable oils, wheat germ, sweet potato, liver, green leafy vegetables, nuts, seeds. DIT 125, Chapter 6 Vitamins 6 Vitamin K Forms: a. phylloquinone - plants b menaquionone - animal tissue c. menadione - synthetic form Functions: 1. Functions in blood clotting 2. Synthesis of bone protein, osteocalcin. Deficiency: • Hemorrhagic disease • Skeletal weakness Toxic: rare 2000 AI: 90 ug women/ 120 ug men Sources: ½ synthesized by bacteria in gut ½ milk, eggs, liver, green leafy, cabbage-type vegetables. DIT 125, Chapter 6 Vitamins 7 Vitamins that are Antioxidants & Beta carotene (Precursor of vitamin A) & Vitamin E & Vitam in DIT 125, Chapter 6 Vitamins 8 Water-soluble Vitamins & Vitamin C & Thiamin & Riboflavin & Niacin & Folate & Vitamin B 6 - Pyridoxine & Vitamin B 12 & Biotin & Pantothenic Acid DIT 125, Chapter 6 Vitamins 9 Vitamin C = Ascorbic acid Functions: 1. Antioxidant-- protects vitamin A and poly- unsaturated fatty acids. 2. Part of the protein collagen. 3. Fights infection, immune system support. 4. Makes hormones RDA: 2000, 75 mg women; 90 for men. + 35mg if smoker. UL: 2000mg or 2 grams Sources: Fruits & vegetables only. DIT 125, Chapter 6 Vitamins 10 Sources of vitamin C Orange juice, ½ c, froz97 mg Strawberries, 1 cup 84 mg Orange juice, chilled 82 mg Kiwo,e m4g Orange, one fresh 70 mg Cantaloupe, 1 cup 68 mg Brocccl,9g Potato, baked, 1 26 mg Tomato, 1 fresh 22 mg Watermelon, 1 cup 15 mg Banano,e 1m0g Apple, one 8 mg Pear, Bartlett, one 7 mg DIT 125, Chapter 6 Vitamins 11 B1 Thiamin, B2 Riboflavin, B3 Niacin Functions: 1. Coenzyme energy metabolism. 2. Needed for normal growth. 3. Release energy from nutrients. Thiamin = nerves .....pork, liver, peanuts Riboflavin = skin/vision……….milk products Niacin = skin/nerve system, GI tract .......meat, fish, poultry, fortified grains & cereals. Niacin made from tryptophan, about 1/2 our need. Deficiency: rare Toxic: Only niacin. DIT 125, Chapter 6 Vitamins 12 Folate Function: New cell synthesis Deficiency: megaloblastic anemia. Neural Tube Defects: anencephaly & spina bifida. 1998 fortification of cereals/grains. DFE = Dietary folate equivalents. a. synthetic 1.7x greater absorption b. natural food sources (green leafy) B 12– Cobalamine Function: New cell synthesis & normal nerve function. Deficiency: pernicious anemia and nerve damage. Intrinsic factor. Animal products only . DIT 125, Chapter 6 Vitamins 13 B6 Pyridoxine Function: 1. Coenzyme, especially protein metabolism. 2. Makes red blood cells. 3. Synthesizes neurotransmitters. Deficiency: fatigue, depression, irritability. Sources: meat, poultry, fish, potatoes, bananas, green leafy and watermelon. Fortified cereals. Toxic: UL 100 mg. Stored in muscles. Can cause permanent nerve damage. Panothenic Acid - B 5 and Biotin Coenzymes in energy metabolism Choline – a potential vitamin. Needed to make lecithin & acetylcholine.