HUN1201 Exam 3 Study Guide
HUN1201 Exam 3 Study Guide HUN1201
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This 9 page Study Guide was uploaded by Christine Notetaker on Thursday March 3, 2016. The Study Guide belongs to HUN1201 at Florida State University taught by Dr. Jafari-Nasabian in Fall 2015. Since its upload, it has received 82 views.
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Date Created: 03/03/16
NUTRITION EXAM 3 STUDY GUIDE CHP 14 Physical Activity ATP must be generated continuously since muscles store only enough ATP for 1–3 seconds of activity When ATP is used up… Creatine phosphate (CP) is used for ATP production o Breaking bond is an anaerobi process o CP stores enough energy for 3−15 seconds When CP is used up… Glucose is used for ATP production o Provides ATP through glycolysis o Used in exercise lasting 30sec to 3min Remember: pyruvate is converted to lactic acid if not enough oxygen (via CORICYCLE) Anaerobic breakdown (coricycle): 2 ATP AEROBIC breakdown: 3638 ATP o Less acid, greater yield, slower, but fuels the body for 3 min to 4 hours Other Fuel for Physical Activity: Triglycerides (fats) o For lowintensity exercise of LONG duration (ex: hiking, resting, sitting, standing etc.) o 2x more energy per gram than carbohydrates o HOWEVER: slowly metabolized (major disadvantage) Carbohydrates o Used for HIGH INTENSITY activity Proteins – NOT USED FOR EXERCISE but for maintaining blood glucose ATHLETES: 4565% of total energy should be CARBOHYDRATES (range depends on the intensity of sport) o High carb consumption in first few hours is ideal Have an increased number and activity of enzymes for fat metabolism (to SPARE CARBS for prolonged, intense training) Require increased protein for those who are training, and less for those already trained. Water acts as: o Temperature regulation, contributes to hydrolysis, transports materials thru body, etc. o Without water… heat syncope (dizziness), heat cramps, and heatstroke o Drink before, during, and after exercise (thirst mechanism NOT RELIABLE already dehydrated when you feel thirsty) and drink enough to maintain body weight CHP 7.5 Micronutrients Micronutrients help in energy metabolism and form/maintain healthy cells and tissues. Vitamins – ORGANIC compounds that either fatsoluble (A, D, E, and K) or fat insoluble (C and B) Fat soluble vitamins: stored in body’s adipose tissue, can be toxic if taken too much; from SUPPLEMENTS not food VITAMIN A (retinol): too much causes fatigue, bone and joint pain, birth defects, liver damage, hair loss, skin disorders, etc. helps prevent night blindness, dry, scaly skin, immunosuppression, and bitot spots on the eye VITAMIN D: too much causes hypercalcemia; prevents osteoporosis VITAMIN E: prevents nerve, muscle, and immune impairment VITAMIN K: prevents impaired blood clotting and supports bone health Water soluble vitamins: not stored in large amounts, thus need to be consumed on a daily/weekly basis; leads to disease or syndromes very quickly if lacking VITAMIN C: too much causes nausea, diarrhea, increased formation of kidney stones; prevents scurvy, bone pain and fractures, depression, and anemia THIAMIN B1: deficiency causes fatigue, apathy, decreased memory, confusion and muscle weakness RIBOFLAVIN B2: deficiency causes swollen mouth and throat, and anemia NIACIN B3: too much causes liver damage, glucose intolerance, and blurred vision; deficiency results in pellagra (vomiting, constipation, or diarrhea) PYRIDOXINE B6: too much causes nerve damage and skin lesions; deficiency causes anemia, confusion, depression, and convulsions COBALAMIN B12: prevents anemia, numbness of extremities, nerve damage, memory lose, and dementia FOLATE: too much masks symptoms of B12 deficiency nerve damage; deficiency causes NEURAL TUBE defects Minerals – naturally occurring INORGANIC substances (all minerals are ELEMENTS and not digested or broken down) Major minerals – require at least 100 mg/day o Sodium, Potassium, Phosphorus, Chloride, Calcium, Magnesium, Sulfur Trace minerals – require LESS than 100mg/day MINERAL AND VITAMIN ABSORPTION Depends on their chemical form Dietary iron: o Heme (meat, fish poultry) is absorbed ~25% o Nonheme (plants and animal foods, ironfortified foods, supplements) absorbed only 35% Depends on other foods within the meal Oxalic acid (tea, spinach) decrease zinc and iron absorption CHEMICAL TRANSFORMATION Many vitamins are modified after eaten and absorbed: B vitamins combine with other substances for phosphorylation to occur Combinations activate the vitamin when the compound is needed (helps regulate metabolic pathways) Micronutrient metabolism: Easier to develop toxic overload on supplements than food Some micronutrients consumed as supplements are harmful to health to certain consumers (ex: A, C, E) Foods provide a balance of micronutrients that work together (better than supplements) Adequate intake of these nutrients has been associated with lower disease risk: o Vitamin C and scurvy o Vitamin D and osteoporosis o Vitamin E and anemia o Vitamin K and impaired blood clotting o Calcium and osteoporosis o Chromium and type II diabetes o Magnesium and muscle wasting in older adults o Selenium and certain types of cancer CHP 8 Nutrients & Energy Metabolism Vitamins and minerals do not directly provide energy needed for generating energy from macronutrients B vitamins are esp. important for energy metabolism by acting as COENZYMES Coenzyme – organic molecule needed for enzyme activity Thiamin, riboflavin, B6, niacin, pantothenic acid, and biotin = energy metabolism Folate and B12 = red blood cell synthesis Cofactor – small simple organic/inorganic ions, usually mineral ions Thiamin (B1 vitamin) – used in metabolism of CARBOHYDRATES and branchedchain AMINO ACIDS Necessary for dehydrogenase reactions (ex: pyruvate dehydrogenase) Assists in production of DNA and RNA and neurotransmitter synthesis Deficiency causes beriberi (two types: dry = nerve damage, wet = heart disease) and Wernicke Korsakoff syndrome (alcoholism related, common in developing countries with diet of plain rice) MAIN SOURCE: meats and grains; whole grain Total cereal Riboflavin (B2 vitamin) – involves OXIDATIONREDUCTION reactions (FAD, FMN in TCA cycle) Part of coenzyme glutathione peroxidase and FAD used in succinate dehydrogenase of TCA cycle Light sensitive (store in opaque milk cartons) Deficiency causes sore throat, swollen mucous membranes MAIN SOURCE: meats, enriched foods, and DAIRY; whole grain Total cereal Niacin (B3 vitamin) – involves OXIDATIONREDUCTION rxns (NADP, NAD in glycolysis) Two forms: nicotinic acid and nicotinamide Made from amino acid tryptophan Deficiency causes pellagra (dementia, dermatitis, diarrhea); common in corn based diets MAIN SOURCE: meats, fish, and enriched grains; whole grain Total cereal Pyriodoxine (B6 vitamin) – metabolism of homocytesine (which increases risk of cardiovascular disease) to cysteine (PLP) Coenzyme in amino acid metabolism and gluconeogenesis Heme and neurotransmitter synthesis Toxicity causes nerve damage and skin lesions; Deficiency causes skin, nerve tissue issues and anemia MAIN SOURCE: Garbanzo beans and Total cereal Folate – plays a role in embryo development by preventing neural tube defects in infants, anemia, and heart disease; sources are green, leafy vegetables, grains, and legumes Cobalamin (B12) – have cobalt center surrounded by a ring structure; only present it animal products (milk, eggs, and dairy products) essential for nervous system functioning Pure vegans are at risk for being deficient which causes anemia Pantothenic Acid (B5) – necessary for FATTY ACID metabolism and CoA FORMATION Needed for synthesizing cholesterol, steroids, and detoxifying drugs (very rarely deficienty) Biotin – coenzyme for fatty acid synthesis, gluconeogenesis Cofactor for CARBOXYLASE REACTIONS (transfers CO2 and carboxyl in reactions) Converts pyruvate oxaloacetate Used in carb, fat, and protein metabolism Consuming RAW EGG over time can cause biotin deficiency Note: B vitamins can be found in enriched and fortified cereals! Choline – used in fat/cholesterol metabolism/transport, homocysteine metabolism, cell membranes, and neurotransmission Types: phosphotidylcholine (AKA lecithin; fat common in cell membranes of foods) and acetylcholine (helps with muscle contraction and cardiac muscle relaxation) Deficiency causes fat accumulation in the liver; toxicity causes vomiting, diarrhea, body odor MAIN SOURCE: widespread in foods, lecithin, milk, peanuts, etc. Iodine – component of thyroid hormones that regulate body temp. and metabolism Important for reproduction and growth Low OR excessive intake interferes with thyroid function o “Goiter" = enlarged thyroid gland o Iodine deficiency disorders (IDDs) Cretinism – mental retardation, stunted growth Hypothyroidism – decreased body temp., fatigue, WEIGHT GAIN, etc. o Hyperthyroidism – high levels of thyroid hormone caused by Graves’ disease WEIGHT LOSS, increased heat production, muscular tremors, nervousness, PROTRUSION OF EYES MAIN SOURCE: saltwater fish, iodized salt Chromium – assists insulin in glucose uptake Important for RNA and DNA metabolism; supports immune function and growth Deficiency: causes rise in blood glucose and insulin levels; more difficult to uptake glucose in cells DOES NOT affect body composition Manganese – cofactor in protein, fat, and carb. metabolism, gluconeogenesis, cholesterol synth., urea formation, and bone matrix synth. Part of antioxidant enzyme (superoxide dismutase) Toxicity: impairs the nervous system, causing spasms and tremors MAIN SOURCE: pineapple and whole grains Sulfur – component of thiamin and biotin; MAJOR mineral ess. for macronutrient metabolism Req. by LIVER for alcohol detoxification; Assists in maintaining acidbase balance Found in amino acids: methionine, cysteine MAIN SOURCE: dietary proteins Inadequate Bvitamin Intake: Shows poor work performance: lower intensity and duration Unenriched processed foods do not have adequate levels of Bvitamins; some Bvit. are lost in milling of grains and need to be replaced by enrichment process! CHP 9 Nutrients in Fluid and Electrolyte Balance 5070% of healthy adults are body fluid o 2/3 is INTRACELLULAR fluid (inside the cell) o 1/3 is extracellular fluid: Interstitial fluid – between cells that make up a particular tissue/organ Intravascular fluid (plasma) – water in blood and lymph; transports blood cells within arteries, veins, and capillaries Fluid composition varies by: Tissue type: HIGHER in lean tissue (70%) vs fatty tissue (1020%) Gender: MEN have more lean tissue, thus more fluid Age: babies and elderly have lower water weight (50%) because of less lean tissue Electrolytes – dissolved substances (solutes) that disassociate in solution into electrically charged IONS POS charge: Na+, K+ NEG charge: Cl, HPO 4 o Extracellular fluid: Na+, Cl o Intracellular fluid: K+, phosphorus Water is a GREAT SOLVENT and dissolves AAs, glucose, and minerals. Watersoluble substances are easily transported in bloodstream… But fatty substances need to be attached or surrounded by WATERsoluble proteins Fluids influence blood volume: Blood pressure RISES when blood volume RISES (risks stroke and heart disease) KIDNEYS help regulate blood volume and pressure Adrenal glands Fluids also maintain body temp. Water has a high heat capacity, so only highsustained heat and energy can raise temp. SWEATING releases heat as evaporation of water cools skin and blood Body fluids protect and lubricate tissues: Cerebrospinal fluid protects the BRAIN and SPINAL CORD, Amniotic fluid protects the fetus, Synovial fluid lubricates joints, Tears cleanse and lubricate eyes, Saliva moistens food for swallowing Electrolytes help regulate fluid balance thru OSMOSIS (water movement from low to HIGH concentration) Osmotic pressure keeps electrolytes from drawing liquid toward them across a semipermeable membrane Electrolytes enable nerves to respond to stimuli: Change in electrical charge across the membrane send nerve impulses to nerve cell + Na , K+ pump ensure that nerve impulses are generated, transmitted, and completed MUSCLE CONTRACTIONS: 2+ Influx of Ca into the muscle from the extracellular space à INTRACELLULAR SPACE o Muscles can relax after contraction once the electrical signal is complete and calcium is pumped out of the muscle cell THIRST MECHANISM (hypothalamus) prompts us to drink when its stimulated by: Increased concentration of salt and other substances in blood A reduction of blood volume/pressure (ex: from sweating, vomiting, diarrhea, etc.) ADH signals kidneys to retain water Metabolic water from body’s chemical reactions contributes 1014% of the body's needs Water Loss: Sensible water loss – water excreted as urine by KIDNEYS or sweat during exercise/heat Insensible water loss – skin (NOT SWEAT) or lungs during exhalation Significant water loss – due to illness, injury, pregnancy, diuretics, etc. *** MEN need 3.7L (1 gallon) and WOMEN need 2.7L of water a day. Sodium (Na+) Affects: blood pressure, acidbase balance, NERVE impulses, MUSCLE contraction/relaxation, glucose absorption (via active transport) Excessive intake may increase urinary calcium excreti in some people, which in turn may increase the risk for BONE LOSS AI: 1,500 mg, most recommend < 2,300 mg/day o Hypernatremia – HIGH blood sodium; people with congestive heart failure or kidney disease cannot excrete sodium well Causes edema (belly swelling) and high blood pressure/volume o Hyponatremia – LOW blood sodium; from prolonged sweating, vomiting, diarrhea, etc. Cause seizures, coma, and FATAL if untreated Potassium (K+) High potassium intake helps maintain a LOW blood pressure + o Remember that K is associated with relaxation of the muscle contraction cycle, so think of a healthy heart (GOOD!) Together with sodium, maintains fluid balance and regulates the contraction of muscles and transmission of nerve impulses. RDA: 4,700 mg/day MAIN SOURCE: fresh fruits, legumes, and vegetables (HIGH in potatoes, yogurt, bananas) Hyperkalemia – HIGH blood potassium levels; alter normal heart rhythm, result in heart attack and DEATH o People with kidney disease are unable to regulate their blood potassium levels and should avoid consuming potassiumcontaining salt substitutes Hypokalemia – LOW blood potassium levels; seen in people with kidney disease or diabetic ketoacidosis; occurs when taking diuretics with extreme dehydration, or eating disorder Chloride (Cl) HCl aids digestion in the stomach; assists immune system in transmission of nerve impulses AI: 2,300 mg/day SOURCE: table salt; hypertension – saltsensitive individuals, lack of Cl is rare (only from eating disorders, severe dehydration, and frequent vomiting) Phosphorus (HPO ) 42 Critical role in BONE formation; Activates or deactivates enzymes (thru phosphorylation) Found in ATP, DNA, RNA, cell membranes, and lipoproteins RDA: 700 mg/day More easily absorbed from animal sources; Phytic acid: plant storage form (BACTERIA IN COLON break it down) Toxicity: from kidney disease or when taking TOO MANY VITAMIN D supplements; causes muscle spasms and convulsions; deficiency is rare Disorders related to fluid and electrolyte imbalance include: – Dehydration – Heatstroke – Water intoxication – Hypertension – Neuromuscular disorders Water Intoxication – Kidneys retain too much water, causing overhydration and hyponatremia (low salt) Hypertension – major chronic disease; increase risk of heart disease, stroke, kidney disease Systolic pressure OVER 140 mm Hg Diastolic pressure over 90 mm Hg o Optimal is 120/80 mm Hg or LESS WHAT CAUSES HYPERTENSION? PRIMARY – unknown cause (9095% of cases) but can help reduce by: o Losing weight o Increasing physical activity o Reducing alcohol intake o Reducing SALT intake o Eating more whole grains, fruits, vegetables, and lowfat dairy foods o DASH diet SECONDARY – caused by kidney disease, sleep apnea, or chronic alcohol abuse (510%) Salt sensitivity in >50% adults with hypertension Kidney and HeartRelated Disorders, Neuromuscular Disorders Kidney Disorders – can lead to edema and fluid retention (due to irregular fluid, electrolyte, and acid base balance) Congestive Heart Failure – heart can no longer pump adequate supply of blood throughout body Electrolyte Imbalances – cause seizures and muscle cramps (due to imbalances of nervous system and impaired muscle function)