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Knocking Over a Post. One end of a post weighing 400 N and

University Physics | 13th Edition | ISBN: 9780321675460 | Authors: Hugh D. Young, Roger A. Freedman ISBN: 9780321675460 31

Solution for problem 98P Chapter 11

University Physics | 13th Edition

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University Physics | 13th Edition | ISBN: 9780321675460 | Authors: Hugh D. Young, Roger A. Freedman

University Physics | 13th Edition

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Problem 98P

Knocking Over a Post. One end of a post weighing 400 N and with height h rests on a rough horizontal surface with µs = 0.30. The upper end is held by a rope fastened to the surface and making an angle of 36.9o with the post (?Fig. P11.90?). A horizontal force is exerted on the post as shown. (a) If the force is applied at the midpoint of the post, what is the largest value it can have without causing the post to slip? (b) How large can the force be without causing the post to slip if its point of application is of the way from the ground to the top of the post? (c) Show that if the point of application of the force is too high, the post cannot be made to slip, no matter how great the force. Find the critical height for the point of application.

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1 NTRI 2000 Exam 3 Study Guide Protein Overview A. The body is made up of thousands of proteins B. They contain nitrogen, carbon, hydrogen, & oxygen C. General functions 1. Regulates & maintains body functions 2. Provides essential form of nitrogen (in the form of amino acids) D. In the developed world: 1. Diet is typically rich in protein (is this an issue) 2. Association between protein intake & mortality 3. Age 50-65 —> decrease in overall, cancer, & diabetes mortality 4. Ages 66+ —> increase in overall/cancer mortality, decrease in diabetes mortality E. In the developing world: 1. Protein deficiency is an issue 2. Important to focus on protein intake in diet planning 3. Aside from water, protein makes up the major part of the lean body tissue Protein structure A. Amino acids are the building blocks of proteins B. Contain nitrogen bonded to carbon C. Makes them unique from carbohydrates and fats D. The proteins in our bodies are made up of 20 different amino acids (actually 21, but standard science says 20) E. Nine are essential (Some are limiting, meaning they have very low amounts in particular foods) F. Eleven are nonessential G. New category 1. Conditionally or acquired indispensable 2. Infants or disease states 2 H. Structure 1. Central carbon 2. Acid group 3. Amino group 4. Side group (Different for each amino acid - gives own characteristics) 5. Hydrogen 6. Peptide bond a. Amino acids are connected together by a peptide bond b. Two amino acids - dipeptide; three amino acids - tripeptide, etc c. Many amino acids - polypeptide d. Some proteins contain multiple polypeptide chains I. Sequence of amino acids is called the protein primary structure (coded in DNA) J. Primary structure leads to the protein higher order structure K. Higher order structure causes the protein to get into a specific shape (native conformation) L. Shape is necessary for the protein to work properly Disruption of normal structure A. Denaturation 1. Heat 2. Strong acids 3. Bases 4. Heavy metals B. Protein basically unfolds 1. Structure is important in proper functioning 2. Only have to change structure a little bit for it to not work properly 3 Protein primary structure A. Determined by the genes (DNA) - kept in the cell’s nucleus 1. Info of the primary structure gets transcribed into messenger RNA (mRNA) 2. mRNA leaves the nucleus & goes tot the ribosome (rough ER) where the protein gets translated (made) B. Protein synthesis 1. DNA contains coded instructions 2. Copies of codes are transferred to the cytoplasm (via mRNA) 3. Amino acids added one at a time 4. With aid of transfer RNA (tRNA) 5. Requires energy Central dogma of biology A. DNA —> protein B. How to change protein structure 1. Genetic alterations 2. Can change the protein’s primary structure 3. Sometimes this isn't a big deal (silent mutation) 4. Sometimes causes significant change in amino acid, which can lead to genetic diseases, such as sickle cell anemia a. A single-base substitution: causes one amino acid to be changed in the polypeptide of the hemoglobin protein b. Alters the higher order structure of the protein c. Protein doesn't work as efficiently (as unaltered version) d. Hemoglobin binds oxygen in red blood cells (heme actually binds) e. RBC have sickle shapes instead of biconcave Digestion of proteins A. Pre-digestion: cooking (slicing the meat), heat denatures proteins, softens food B. Digestion begins in the stomach 1. Acid (HCl) denatures protein 2. Pepsin (enzyme) breaks down peptide bond of proteins resulting protein fragments 4 C. What controls pepsin & stomach acid release 1. Gastrin - hormone 2. Released in response to thinking about food and chewing and digesting food D. Partially digested proteins and other nutrients is called chyme E. Movement to small intestine once processed into chyme 1. Release of CCK (hormone) movement of chyme into small intestine stimulates cells to release CCK 2. CCK caused pancreas to release proteolytic enzymes (trypsin, chymotrypsin) (proteolytic: cleaving proteins) 3. Pepsin inactivation (elevated pH) F. Several peptidases are found in brush border 1. Small peptides (2-3 amino acid in length) & free amino acids are absorbed by active transport 2. Any intracellular peptides are digested by enzymes within cells 3. Taken up by capillaries and taken to the liver via the portal vein 4. Free amino acids used as building blocks for liver proteins are then broken down for energy, released into blood, and converted to nonessential amino acids, glucose or fat G. Sensitivity to proteins 1. Gluten / Gluten sensitivity (celiac disease) a. Protein found in grains like wheat, rye, and barely that gives backed goods their bought, elastic structure b. Incomplete gluten breakdown in small intestine leaving small peptides and amino acids c. Celiac disease-inflammatory response to small peptides/ amino acids d. Autoimmune response, genetic predisposition (immune system attacks “foreign” bodies; autoimmune: attacking self) e. Prevalence is 1 in 133 f. In people with related symptoms: 1 in 56 g. Blood test looks for antibodies which results in a biopsy of intestines h. If positive, remove all gluten from diet 5 Function of protein in body A. Producing vital body structures 1. Body is in a state of constant protein turnover 2. Producing proteins & disassembling proteins B. What happens with protein inadequacy 1. Muscles, blood proteins, & vital organs decrease in size 2. Brain resists breakdown C. Maintain fluid balance 1. Blood proteins attract fluids 2. Fluid shifts into tissues - edema D. Contributes to acid-base balance 1. Act as buffers - maintain pH within a narrow range 2. Keeps blood slightly alkaline E. Form hormones and enzymes 1. Hormones- communication between cells 2. Enzymes- Catalyzes reactions in cells F. Transport and signaling receptors 1. Transport- bring nutrients into the cell 2. Signaling receptors and communicating in the cell G. Immune function 1. Antibodies production (move DNA around to come up with new combinations) 2. What happens with protein inadequacy Decrease in immune function H. Providing energy (direct) and indirect (glucose) I. Contribute to satiety Infant digestion of proteins A. Up to 4 fo 5 months of age B. The GI tract is somewhat permeable to small proteins (whole proteins can be absorbed) C. If breastfed, this allows antibodies to be passed from mother to baby (immune system is learning difference between self and foreign) D. Waiting until the infant is at least 6-12 months of age before introducing some foods than can cause allergies (introduce in a step-by-step manner) 6 Functions of Protein in the Body A. Provides energy 1. Calorie restriction 2. Prolonged exercise B. However, cells use primarily fats and carbohydrates 1. Why It’s efficient 2. It wastes calories to metabolize (break down) amino acids for energy C. Forms glucose 1. Amino acids can be converted into glucose 2. This happens when glucose is low 3. Through glycogenic amino acids 4. There are nonessential and essential amino acids 5. In starvation, muscle wasting and edema results from protein breakdown D. Contributes to satiety 1. Provides the highest feeling of satisfaction after eating 2. May contribute to collie control during weight loss 7 The need for protein A. Only need it if you aren't growing (ie adults) B. Only need enough protein to replace what’s been lost daily C. This is often called protein breakdown/protein turnover Protein RDA A. 0.8 g of protein for every 1 kg of healthy body weight B. For an average person (150 lbs = 70 kg) this means 56 grams of protein C. This is about 10% of total calories D. Food and Nutrition Board want it closer to 35% E. In the U.S. the typical protein intake is about 100 grams for men and 65 grams for women F. Typical protein intake is greater than what is needed G. In the western diet, 70% of dietary protein comes from animal sources H. Water packed tuna is the most nutrient-dense source of protein I. Top contributors of protein in the American diet include beef, poultry, milk, white bread, and cheese J. The problem with so many animal sources is that they tend to be low in fiber, some vitamins, phytochemicals, and high in saturated fat and cholesterol K. Red meat is very strongly linked with colon cancer, especially in any processed form L. High protein diet is stressful on the kidneys M. Some studies show that high protein diets are associated with calcium losses in urine Complete protein in plants A. Quinoa- grain like B. Amaranth- seeds are ground into flour and the leafy greens rival swinish and kale for nutrients C. Soybeans- made up of 47% protein D. Buckwheat- not wheat, but actually relayed to rhubarb; the grain is ground into flour 8 Alternatives to the typical high-protein diet A. Vegetarian- no meat at all B. Semi-vegetarian- no meat typically but occasionally consume fish and poultry or meats infrequently C. Vegan- no animal products, which can cause a lot of health issues 1. Need complimentary proteins 2. Nutrient deficiency concerns, such as iron, vitamin B12, zinc, calcium (dairy), omega-3 fatty acids (fish/fish oil) D. Animal proteins are considered to be complete proteins/high quality, because they contain all essential amino acids in abundance E. Plant proteins tend to be incomplete proteins/low quality, because they are low in one or more of the essential amino acids F. Plant sources of proteins 1. Nuts 2. Seeds 3. Legumes G. With a vegetarian diet, there are specific protein requirements 1. Grains and nuts are low in the amino acid lysine 2. Vegetables and legumes are low in methionine 3. Complementary proteins combine two or more of the following to compensate for deficiencies in essential amino acids needed for each proteins Protein consumption complications A. Gluten sensitivity B. Allergies related to peanuts, tree nuts, shellfish, eggs, milk, soy, wheat, fish C. The immune system mistakes food protein for harmful invaders D. 8 foods account for 90% of food-related allergies E. Reactions range from intolerance to fatal allergic reactions 9 10 Complete protein in plants A. Quinoa- grain like B. Amaranth- seeds are ground into flour and the leafy greens rival swinish and kale for nutrients C. Soybeans- made up of 47% protein D. Buckwheat- not wheat, but actually relayed to rhubarb; the grain is ground into flour Protein-Calorie Malnutrition A. In the developed world, diet is typically rich in protein B. In the developing world, protein deficiency is an issue, which is important in diet planning C. It is rare to see protein deficiency in developed countries, but it is seen in certain populations D. In developing countries, it can stunt growth and increase the risk of infection E. Protein-Energy Malnutrition called marasmus which is apparent in starvation or where there is insufficient protein and calories F.Kwashiorkor is marginal amount of calories but severe protein deficit G. These diseases are commonly found in Africa H. In the U.S., it can be found in hospital patients, long-rem care residents, community- dwelling adults, dialysis patients (In every one of these cases, the victims are all older adults over 65 years old) 11 Megadoses of Vitamins A. Beyond estimates of needs B. Not in a balanced diet C. 2-10x human needs D. Usually through supplements E. Increased risk for toxicity symptoms F. Proven useful in treating several nondificiency diseases G. Oversupplementation can leads to vitamin levels building up over time H. Vitamins can be stored within the body I. Fat soluble vitamins (especially vitamin A) have the potential to reach toxic levels Vitamin Preservation A. The riper the food, the more vitamins B. Vitamins lost from time picked to consumed C. Best to eat as soon as possible after harvest D. Water soluble vitamins destroyed by improper storage or excessive cooking E. Heat, light, air, cooking in water, alkalinity F. How to preserve vitamins in foods 1. Freezing- best method 2. Blanching- destroys enzymes that degrade the vitamins Two Classes of Vitamins A. Fat soluble vitamins- A, D, E, K 1. absorbed in chylomicron 2. Stored in liver and fatty tissue 3. Not readily excreted B. Water- soluble vitamins- C and B vitamins 1. Absorbed through the capillaries 2. In general, not stored to a great degree 3. Excess excreted in urine 12 Vitamin A (Retinoids) and Carotenoids A. Vitamin A (preformed) 1. Retinol 2. Retinal 3. Retinoid acid 4. Note- exist only in animal products and in supplements B. Carotenoids 1. Contained in plant pigments 2. Phytochemicals- polyphenols 3. Principle pigments for red, orange, yellow and green colored fruits/vegetables 4. Some are precursors to vitamin A, such as provitamin A 6. Beta-carotene- carotenoid that can be sufficiently absorbed and converted into retinol Functions of Vitamin A and Carotenoids A. Health of epitheal cells and immune function 1. Maintains health of epithelial cells that line internal/exterbak surfaces 2. Lungs, intestines, stomach, vagine, urinary tract, bladder, eyes and skin 3. Healthy epithet tissues serve as important barriers to infection B. Vision 1. Night blindness- vitamin A deficiency disorder that results in loss of ability to see under low-light conditions 2. Vitamin A important for light-dark vision and color vision 3. Retina consist of rods and cones 4. Rods detect black and white, night vision 5. Cones responsible for color vision 6. Lutein and zeaxanthin in high concentrations in retina a. Found in leafy green vegetables b. Help prevent macular degeneration c. Food sources may help decrease risk of calories C. Cardiovascular Disease 1. Carotenoids may decrease rise by preventing oxidation of LDL 2. Recommendations to consume 5 servings a day of fruit and vegetables 13 Vitamin A Deficiency A. Leading cause of blindness worldwide B. Eye cells affected- inability to adjust to dim light, causes night blindness C. Xerophthalmia: hardening of cornea and drying of the surface of the eye, which can result in blindness Vitamin A Deficiency Risk A. North Americans are low risk- typical American diets contain preformed vitamin A B. Worldwide, 1/3 of children suffer from deficiency C. Attempts to reduce this problem: 1. Promote breastfeeding 2. Vitamin A megadoses 2x a year 3. Fortification of sugar and margarine Getting Enough Vitamin A and Carotenoids A. Preformed vitamin A: Liver, fish, fish oils, fortified mild, butter, yogurt, eggs B. Carotenoids: Dark green and yellow-orange vegetables C. Cooking improves bioavailability D. RDA expressed in retinol activity equivalents (RAE)- takes into account both preformed and carotenoid source E. Typical American diets sufficient- supplementation unnecessary for most people Avoiding Too Much Vitamin A and Carotenoids A. Excess linked to birth defects and liver toxicity- by preformed vitamin A B. Carotenoids in large amounts do not cause toxic effects C. Hypercarotenemia: skin turns yellow-orange, particularly hands and soles of feet,; disappears when intake decreases Vitamin D – Fat soluble A. Not just a vitamin but is also a hormone B. Requires skin, liver, and kidneys C. The body can make vitamin D when exposed to UVB light D. Exposure time depends on skin color, age, time of day, season, and location 14 Functions of Vitamin D A. Helps regulate blood calcium levels and bone metabolism (works with parathyroid hormone) 1. Helps regulate calcium and phosphorus absorption from intestine 2. Regulates the deposition of calcium in bone 3. Regulates calcium excretion from kidney B. Helps in the development and can decrease risk of cancer in skin, colon, prostate, ovary, and breast Deficiency of Vitamin D A. In children causes rickets- bow legs, enlarged head/joints/rib cage, deformed pelvis B. In adults causes osteomalacia 1. Softening of bones 2. Leads to fracture of hips and other bones Vitamin D toxicity A. UL – 50 micrograms per day B. Too much can cause calcium deposits in soft tissues C. Can’t develop vitamin D toxicity because of too much sunlight Vitamin D in foods A. Fatty fish B. Fortified milk and yogurt C. Some breakfast cereals Vitamin E – Fat soluble A. A family of compounds called tocopherols B. Alpha Tocopherol – main form in the body C. Gamma Tocopherol – Foods D. Acts as a fat-soluble antioxidant E. Resides mostly in cell membranes 15 Vitamin E – Antioxidant role A. Oxidizing agents are seeking electrons B. Example: the double bonds of unsaturated fatty acids in phospholipids C. Oxidizing agents can create free radicals D. As an antioxidant, vitamin E has electrons it can give up to the oxidizing agent E. Result: protects components of the cell (phospholipids) Deficiency of Vitamin E A. Can cause cell membrane to break down B. This is particularly true in red blood cells, called hemolysis, which can lead to hemolytic anemia C. Premature infants are particularly at risk D. Smokers Vitamin E toxicity A. UL – 1000 milligrams per day B. High doses can interfere with clotting mechanism in body, leading to a hemorrhage C. Thus, people at risk are individuals taking anticoagulants, high does of aspirin or are deficient in vitamin K Vitamin E – in foods A. Plant oils (salad dressings, mayonnaise) B. Ready-to-eat cereals C. Dry roasted sunflower seeds and almonds D. Some fruits and vegetables Vitamin K A. Vitamin K is vital for blood clotting B. The “K” of vitamin K comes from the Danish spelling of coagulation C. Vitamin K also activates proteins present in bone, muscle, and kidneys to give calcium binding ability to these organs D. Poor vitamin K intake is associated with hip fractures in women E. About 10% of our vitamin K is made by bacteria living in our GI tract 16 Vitamin K in foods A. Liver, green leafy vegetables (kale, turnip greens, dark green lettuce, spinach, brussel sprouts) asparagus, broccoli B. Oils – soybean and canola Vitamin K Toxicity A. There is no risk of toxicity, so no UL has been set B. Megadoses may reduce the effectiveness of anticoagulation medications Water Soluble Vitamins A. Vitamin C 1. What is it a. Compounds with antiscorbutic activity b. Dietary form is ascorbic acid c. Similar structure to glucose d. Essential for humans and some other species 2. Foods: a. Citrus fruit b. Green peppers c. Brussel sproutS d. Strawberries e. Tomatoes f. Fortified drinks 3. Stability a. Vitamin C is rapidly lost by processing and cooking food b. It is unstable in the presence of heat, iron, copper or oxygen 4. Functions: a. Formation of collage- strengthens structural tissues by increasing cross connections between amino acids b. Formation of other compounds, such as the synthesis of carnitine; formation of serotonin and norepinephrine c. Antioxidant- can readily accept and donate electrons 17 B. B vitamins (function as precursors to coenzymes) 1. Thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B6, folate, vitamin B12 2. Occur in many of the same foods 3. So a lack of one B vitamin may mean others are also low in the diet 4. B vitamin deficiency symptoms typically occur in the brain, nervous system, skin and GI tract 5. Several b vitamins are in whole grains, but are removed during milling process 6. To counter these losses, flour in the U.S. is enriched with four b vitamins (thiamin, riboflavin, niacin, and folate) C. Vitamin B6- Pyridoxine 1. Needed for the activity of many enzymes such as carbohydrate, protein, and fat metabolism; particularly important in amino acid metabolism, aids in transferring nitrogen group 2. Necessary for the synthesis of neurotransmitters by allowing nerve cells to communicate; important in the synthesis of hemoglobin and white blood cells; and necessary for conversion of tryptophan to niacin D. Vitamin B12 1. Contains the mineral cobalt 2. Must bind to intrinsic factor, made by the stomach, in order to be absorbed 3. Defective B12 absorption is common in older people 4. Animal products: meat, milk, poultry, seafood, eggs, ready to eat cereals 5. Required to convert folate into its active form 6. Maintains the myelin sheaths that insulates neuron- destruction of myelin causes paralysis and perhaps death 7. Pernicious anemia: means "leading to death;” symptoms include weakness, sore tongue, apathy, tingling in the extremities; infants of vegans are at risk 18 E. Folate 1. The term folate encompasses a variety of forms of the vitamin 2. Folic acid is the synthetic form 3. Functions a. Single carbon supplier or donor b. Coenzyme helps c. Form DNA d. Metabolize various amino acids and their derivatives e. Bone marrow produces immature red bloood cells (megaloblasts) which causes megaloblastic anemia, which can cause an inflammation of tongue, mental confusion, depression, and problems with nerves 4. Deficiency a. 10% of population has genetic defect in the metabolism of folate, and as a result, they need up to double the RNA to compensate for the defect, and has be linked to neural tube defects in the fetus along with maternal folate deficiency b. Affects about 2000 infants a year in U.S., such as spina bifia to anencephaly. This occurs when the neural tube crosses within first 28 days of pregnant, which is a time when many women are not even aware they are pregnant, therefore, it is crucial for all women of child bearing age to have an adequate intake of folate 5. Folate in food a. RDA- 400 micrograms per day b. Pregnant- 600 micrograms per day c. The name folate comes from foliage d. Green leafy vegetables, organ meats, sprouts, other vegetables, dried beans, and orange juice e. Suceptible to destruction by heat 19 F.Thiamin (B1) 1. Help release energy from carbohydrates and certain amino acids 2. Beriberi ("I can't, I can’t") 3. There is no UL for thiamin 4. Pork products, whole grains, ready to eat cereals, enriched grains G. Riboflavin (B2) and Niacin (B3) 1. Both aid in energy metabolism 2. Both are coenzymes 3. Riboflaviin - flavin adenine dinucleotide (FAD) 4. Niacin - nicotinamide adenine dinucleotide (NAD) H. Pantothenic acid 1. Aids in the energy metabolism 2. Coenzyme - coenzyme A 3. Deficiency among healthy people who eat a varied diet is unlikely Water A. Life cannot exist without water B. Water is a solvent for chemicals in the body, allowing chemical reactions to take place C. Water makes up 50%-70% of the body’s weight Fluid Compartments A. Intracellular = water inside the cell B. Extracellular = water outside the cell C. Intracellular fluid is also referred to as ICF D. Water can move (diffuse) between compartments E. Ions control the movement of eater between the intracellular and extracellular compartments F. Ions are minerals with an electrical charge (also called electrolytes) G. The movement of water across a semipermeable membrane is called osmosis 20 Functions of Water A. Solvent for chemicals in the body, allows chemical reactions to take place B. Contributes to body temperature regulation (sweat) C. Helps remove waste products by dissolving them into the water D. Cushions and lubricants (knees, joints, saliva, bile) E. Water is not stored, but precisely regulated by the nervous, endocrine, digestive, and urinary systems What if we don't get enough water A. 1-2% loss- thirst mechanism occurs B. Antidiuretic hormone (ADH) helps the body conserve water 1. Released by pituitary 2. Communicated with kidney to conserve water C. Alderstone 1. Released from adrenal gland when blood volume decreases 2. Communicates with kidney to conserve water Can you consume too much water A. Too much in a short period of time leads to water intoxication/poisoning 2. Dilutes sodium levels 3. Symptoms- nausea, mental confusion, vomiting, headaches, muscle weakness, convulsions Bioavailability of minerals A. Bioavailability- how much we take in B. Is dependent on 1) how much food and 20 our ability to absorb it C. The amount in a food doesn't generally reflect the bioavailability D. Minerals from plants 1. Depends on the soil its grown in 2. May be jocund by dietary fibers and other molecules E. Minerals from animal source 1. Are not as dependent on soil conditions 2. Absorbed better than plant sources because fewer binders and dietary fiber 21 Mineral Binders A. Oxalates (spinach)- binds calcium B. Phylates (grains)- binds calcium, iron zinc, others C. Mineral-mineral interactions- calcium-iron; zinc-copper D. Vitamin-mineral interactions Mineral Toxicities A. Minerals can be toxic in high levels, especially trace minerals B. Not a problem when food is the source, but can be from mineral supplements Calcium (Ca) A. Most abundant mineral in the body B. 99% of body calcium is in the bone 1. Integral part of bone structure 2. Storehouse for calcium in the blood C. Adults absorb about 25% of the calcium in foods eaten D. Increases in infants and during pregnancy (60%) Serum Calcium (functions) A. Regulates transport of ions across cell membrane (important in nerve transmission) B. Helps maintain blood pressure C. essential for muscle contractions D. Essential for secretion of hormones, enzymes, neurotransmitters, etc. E. Essential for blood clotting Possible Health Benefits A. Possible links between calcium intakes and risks of certain cancers, kidney stones, hypertension, high blood cholesterol, and obesity B. Osteoporosis- decreased bone mass related to aging, genetic background, and poor diet; leads to 1.5 million bone fractures per year just in the U.S., bones become brittle 22 Bone Density A. Reaches a peak in 20s B. Levels off in 30s C. Lose after 40s D. Need to build up bone density when you are young E. How to maintain adequate bone density: 1. Adequate amount of calcium and vitamin D in your diet 2. Exercise 3. Estrogen Calcium in foods A. AI- 1000-1200 mg per day B. Foods such as dairy products (milk, cheese yogurt), breads, rolls, leafy vegetables (kale, collards, turnips, mustard greens), calcium fortified products, supplements (calcium-based antacids) C. UL- 2500 mg per day (risk of kidney stones) Sodium (Na) A. Absorb about 100% of Na consumed B. 30-40% found in bone C. The major positive ion found in extracellular fluid D. Functions- fluid balance between compartments, nerve impulse conduction, absorption of glucose Sodium Sensitivity A. For most people, the body will adjust to higher sodium intake by increasing urine output B. 10-15% of adults are sodium sensitive C. High sodium intake leads to increased blood pressure D. UL- 2300 mg per day 23 Sodium Deficiency A. Very rare- excessive perspiration, persistent vomiting, diarrhea B. Leads to muscle cramps, nausea, vomiting, dizziness, coma Chloride (Cl) A. An ion of chlorine B. Major negative ion for extracellular fluid C. Used in producing stomach acid (HCl) during immune response of white blood cells Potassium (K) A. Postive ion in a intracellular fluid compartment B. 95% of bodys potassium C. Like sodium, potassium is important in fluid balance and nerve impulse transmission D. Unlike sodium, increasing potassium intake is associated with lower blood pressure E. Increased risk of deficiency-people on diuretics to treated high blood pressure, alcoholics, certain eating disorders F. Can lead to heart failure G. Too much- due to kidney failure, can stop heart H. AI- 4700 mg per day I. Foods include unprocessed foods, potatoes, plums, avocados, bananas, cantaloupe, honeydew melon, raisins Trace Minerals A. Iron, Zinc, Selenium, Iodine, Copper, Chromium, Fluoride, Chromium, etc. B. All are toxic in excess Iron (Fe) In every cell of the body B. Absorb about 18% of that present in food C. Most iron associated with hemoglobin (RBC) and myoglobin (muscle)- heme iron D. Other types are called non-heme iron E. When RBCs die, iron is recycled F. Therefore, we lose very little, except during bleeding 24 Iron Absorption A. Heme iron is more readily absorbed than non-heme iron B. Vitamin C (75 mg) enhances absorption of non-heme iron C. Tannins in tea and phytates in grain inhibit iron absorption Iron Deficiency A. Anemia- decreased oxygen-carrying capacity of the blood 1. Lower number of RBCs 2. Less oxygen to the cells 3. Present in about 30% of the world population 4. Half of which is due to low iron B. Neurological dysfunction called Pica, cravings for odd things such as ice, dirt, etc. C. Result is impaired physical and mental activity 1. Fatigue, loss of appetite 2. Decreased learning ability 3. Decreased attention span Iron Toxicity A. Hemochromatosis B. Bronzing of the skin C. Iron builds up in the liver and the blood D. Will lead to organ damage, especially in the liver and heart E. UL- 45 mg/day F. Somach irritation, toxicity can be life threatening Zinc A. About 40% of dietary Zn is absorbed B. Zinc is a cofactor for up to 200 different enzymes C. Functions: 1. Growth, would healing 2. Sexual maturity 3. Taste perception 4. Immune system, indirect antioxidant 25 Zinc Deficiency A. First recognized in the 1960s in boys from the middle east B. Diet low in animal protein, exclusive use of unleaded bread C. Had a severe impact on their growth/maturity D. Symptoms include acne-like rash, diarrhea, lack of appetite, delayed wound healing, impaired immunity, reduction of sense of taste and smell, hair loss E. RDA men: 11 mg F. RDA women 8 mg G. Average Americans consume 10-14 mg/day H. Absorption depends on body needs 1. Phytic acid binds to zinc and limits availability 2. High calcium intake decreases zinc absorption 3. Zinc competes with copper and iron for absorption How to Avoid Too Much Zinc A. UL: 40 mg B. Excess interferes with copper metabolism C. Toxicity interferes with copper metabolism D. Toxicity can occur from supplementation or overconsumption of zinc-fortified foods E. If your intake is over 100 mg, you may experience diarrhea, cramps, nausea, vomiting, loss of appetite Selenium A. Indirect antioxidant, works with vitamin E to help protect cell membranes from oxidizing agents B. Binds to enzymes- protects against oxidation C. May have anticancer properties D. Found in some areas of China E. People developed characters muscle and heart problems associated with inadequate selenium intake F. RDA- 55 micrograms per day G. 400 micrograms per day (hair loss) H. Foods include eggs, fish, shellfish, grains, seed grown in soils containing selenium 26 Iodide A. Ion of iodine B. Used in the production of thread hormone C. Thyroid hormone helps regulate metabolic rate and promotes growth/development Iodide Deficiency A. Deficiency- cells of thyroid enlarged in attempt to trap more iodine (goiter) B. People are sluggish and gain weight C. During pregnancy, deficiency can cause extreme and irreversible mental and physical retardation of developing baby (cretinism) Getting Enough Iodide A. RDA and DV 150 micrograms B. Half teaspoon od iodide-fortified salt supplies this amount C. Most North Americans consume more than RDA (iodized salt, dairy products, grain products) D. UL: 1.1 miligrams E. High amounts may appear can inhibit thyroid hormone synthesis and may be more commonly seen in individuals consuming a lot of seaweed Copper (Cu) A. 12-75% of Copper is absorbed B. Involved in: 1. The metabolism of iron by functioning in the formation of hemoglobin and transport of iron 2. The formation of connective tissue 3. Is a cofactor for antioxidant enzymes C. Sources include: liver, legumes, seeds, whole grains breads and cereals, cocoa D. Form found in supplements not readily absorbed E. Absorption highly variable- higher intakes associated with lower absorption efficiency F. Phytates, fiber, excess zinc and iron supplements interfere with absorption G. Average intake: 1 mg men, 1.6 g men 27 H. Single dose greater than 10 milligrams can cause toxicity, and include symptoms such as GI distress, vomiting blood, tarry feces, damage to liver and kidney I. Toxicity cannot occur with food, only supplements J. Wilson’s disease-a genetic disorder that results in accumulation of copper in tissues, characterized by damage to the liver Should You Take A Supplement A. There is evidence to support the widespread use or multivitamin and mineral supplements is mixed 1. Little risk of harm from consuming a multivitamin 2. Most studies indicate no discernible advantage 3. NIH concluded that the present evidence is insufficient to recommend for or against B. Only a few studies of vitamin and mineral supplements prevent deficiencies or chronic disease 1. High dosage of one nutrient can affect the absorption and metabolism od other nutrients 2. Some supplements can interfere with medications C. Safest and healthiest way to obtain it is from your food D. Fortified foods can help fill gaps Which supplement should you choose A. Choose a nationally recognized brand B. Be sure not to exceed UL from supplements and fortified foods C. Look for UA Pharmacopeial Convention (USP) label D. Excess can cause damage to the lover, nervous system, and other organs 28 Dietary Supplements A. Who regulates them 1. Dietary Supplement Health and education Act (1994) (DHSEA) 2. Established by Congress 3. Gives FDA authority to “regulate” them 4. Established the Office of Dietary Supplements under the DIH 5. DSHEA definition: a. Vitamin, mineral, herb, or other botanical amino acid b. A dietary substance to supplement the diet, which could be an extract or a combination of the first four ingredients on the list B. Who needs them 1. Use of dietary supplements is a common practice among North Americans and generates about $35-36 billion annually 2. Can be sold without proof that they are safe or effective 3. Supplement makers can make broad “structures of function” claims about their products, but cannot claim to prevent, treat, or cure a disease Homeopathic Remedies A. Regulated by the FDA B. The FDA doesn't look or evaluate them for safety or effectiveness C. There is little evidence to support homeopathy as an effective treatment for any specific condition D. Must contain active ingredients that are listed in the homeopathic Pharmacopeia of the US (HPUS)

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Chapter 11, Problem 98P is Solved
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Textbook: University Physics
Edition: 13
Author: Hugh D. Young, Roger A. Freedman
ISBN: 9780321675460

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