NTDT 200 EXAM 2 STUDY GUIDE
NTDT 200 EXAM 2 STUDY GUIDE NTDT200
Popular in Nutrition Concepts
Popular in Nutrition and Food Sciences
verified elite notetaker
This 12 page Study Guide was uploaded by Heather Cronin on Friday August 26, 2016. The Study Guide belongs to NTDT200 at University of Delaware taught by Jennifer Linton in Winter 2016. Since its upload, it has received 9 views. For similar materials see Nutrition Concepts in Nutrition and Food Sciences at University of Delaware.
Reviews for NTDT 200 EXAM 2 STUDY GUIDE
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 08/26/16
The Lipids Lipid family: triglycerides, phospholipids, sterols Triglycerides o Most abundant fat in the body and food o Energy per gram is greater than carbs due to more carbon and hydrogen o Triglycerides: 1 glycerol, 3 fatty acids o Roles: Provides cell with energy Adipose tissue stores body fat Skin insulation Shock absorption Phospholipids o 5% of diet o Lecithin is most known o Found in eggs, liver, soybeans, peanuts and wheat germ o Soluble in fat and water o Used as emulsifiers in food industry o Hydrophobic and hydrophilic Sterols o Cholesterol most known Liver makes 8001500 mg daily o Plant sterols interfere with cholesterol absorption o Found in meat, eggs, seafood, poultry and dairy Fatty Acids o Have even # of carbons o Saturated vs. Unsaturated: presence of hydrogen o Double bonds o Essential: 18carbon polyunsaturated fatty acids Omega 3: linolenic Body doesn’t produce, makes DHA & EPA Omega 6: linoleic Vegetable oil and meat Eicosanoids: made from omega 3 and 6s o Omega 9: monounsaturated Fats & Oils o Polyunsaturated fats (oils) are liquid Sunflower, canola, corn and soybean oil o Saturated fats are solid Cocoa butter, coconut oil Stability o Fats spoil when exposed to oxygen o Polyunsaturated fats (oils) spoil quicker because their double bonds are unsteady Hydrogenation o Protects against oxidation o Makes liquid oils more solid o Partial hydrogenation is most common (spreads) Lipid Digestion o Fats are hydrophobic o Goal of fat digestion: dismantle triglycerides Breakdown into monoglycerides, fatty acids, and glycerol o Mouth Lingual lipase is high in infants o Stomach Contractions and gastric lipase o Small Intestine Cholecystokinin (CCK) Liver makes bile (made of cholesterol) Gall bladder releases bile into small intestine Absorption o Lipids go directly into bloodstream o Lymphatic system is packed with proteins called chylomicrons, which function as transport vehicles o Liver is bypassed Transport o 4 lipoproteins Chylomicrons largest and least dense, liver removes remnants from blood Very low density lipoproteins (VLDL) made in liver Low density lipoprotein (LDL) cause heart disease High density lipoprotein (HDL) removes cholesterol from cells and carries it to liver for recycling Fat supplies 60% of energy during rest Fat and lean protein are used during starvation Health Effects of Bad Fats o Heart disease is the #1 killer o High LDL cholesterol is a risk factor for heart disease o Trans fats increase LDL and decrease HDL o Lean protein, lowfat items, fruits, veggies and whole grains protect against heart disease o Dietary cholesterol doesn’t impact blood cholesterol Recommended Intakes of Fats o 2035% calories from fat o Less than 10% of calories from saturated fat o 1 tsp with each meal Health Effects of Mono and Polyunsaturated Fats (Good) o Replace saturated fats with unsaturated fats to lower LDL Salmon, olive oil, nuts o Regular consumption of omega3s suppresses inflammation Salmon, tuna, sardines Groceries o Fatsoluble vitamins: A, D, E, K o Provide flavor, texture & palatability o Vegetables, fruits and grains provide phytochemicals o Fat replacers can cause diarrhea, so you don’t absorb nutrients Proteins Average daily intake is 80g High protein intake is 100+g per day Proteins contain carbon, hydrogen, oxygen and nitrogen o Only macronutrient that contains nitrogen Amino Acids o 20 amino acids 9 essential (indispensable) 11 nonessential (dispensable) Insulin has 51 amino acids o Peptide bonds link amino acids through condensation reaction o Sequencing: primary, secondary, tertiary, quaternary o Hemoglobin red blood cell protein that carries oxygen from the lungs to the tissues of the body Contain 80% of body’s iron o Amino acids make other compounds Tyrosine makes epinephrine and norepinephrine Tryptophan precursor for niacin and serotonin Deaminate into ammonia and keto acid by stripping nitrogen Makes fats o Cells can build essential or nonessential amino acids and convert ammonia to urea Production of urea relevant to protein intake Excreting Urea o Liver releases urea into blood o Liver disease is caused by high blood ammonia o Kidney disease caused by high blood urea o Water is required to dilute and excrete urea Denaturation of Proteins o Occurs through cooking, spoiling or digestion in stomach acid o Disrupts stability of proteins Coil and lose shape Protein Digestion o Mouth o Stomach hydrolysis of protein is initiated; hydrochloric acid denatures proteins With age, hydrochloric acid decreases, so pepsinogen and pepsin are not activated as easily o Small intestine Protein Absorption o Unused amino acids are transported to liver Protein Synthesis o Transcription: messenger RNA (mRNA) made from DNA template mRNA carries code to ribosome (protein factory) o Translation: mRNA direct sequence of amino acids and protein synthesis Sickle cell anemia: sickleshaped red blood cells, interferes with oxygen transport and blood flow Gene expression: cell converts genetic code into RNA and protein o Each cell only makes the protein it needs Structures o Average lifespan of a cell is 30 days o Catabolic reactions: breakdown o Anabolic reactions: buildup o Catalysts permit reactions to occur quickly without changing themselves Roles of proteins o Hormones o Edema: excess of fluids in tissues and swelling o Acidbase balance: 7.357.45 o Antibodies produced when body detects invading antigens Virus, bacteria, toxins Each antibody attacks specific antigen o Alternate source of energy/glucose o Blood clotting: fibrin Protein metabolism is a continuous turnover Nitrogen Balance o Determines required protein intake o Zero balance: intake=output Synthesizing more than you degrade creates positive nitrogen status Protein added Infants, children, pregnant women Degrading more than you synthesize creates negative nitrogen status Caused by severe stress Protein Quality Factors o Digestibility Animal protein has 9099% digestibility Plant protein has 7090% digestibility o Amino Acid Composition Limiting Amino Acids: essential amino acids supplied in amount less than what’s needed for protein synthesis Reference and Complementary Proteins o Reference protein: standard against which to measure quality of other proteins o Highquality proteins: contain all 9 essential amino acids o Complementary proteins: lowquality proteins combined to provide adequate levels of essential amino acids Health Effects of Proteins o Protein deficiency causes stunted growth, impaired brain and kidney function o High homocysteine is a risk for heart disease o Osteoporosis 1 gram of protein= 20 milligrams of calcium o The more protein you eat, the harder your kidney must work Recommended Intakes o Only source of essential amino acids and nitrogen o 1035% of calories o RDA recommends 0.8 grams of protein for every kilogram you weigh (divide pounds by 2.2) o 1 oz of proteinpacked food=7 grams of protein o 1 cup of milk= 8 grams of protein o Fruits and vegetables= 23 grams of protein o KEY DIET PLANNING PRINCIPLE IS MODERATION The Vitamins Vitamins are organic (contain carbon) Bioavailability: rate and extent that a nutrient is absorbed and used by the body o Primary excretory route for watersoluble vitamins is the kidney o Influential factors: Efficiency of digestion Nutrition status Method of food prep Source of nutrient Other foods consumed Precursors (Provitamins): inactive forms of vitamins found in food o Converted to active in body o Ex. Betacarotene is precursor for vitamin A B Vitamins o Help body use macronutrients for fuel (needed for energy) o Coenzymes: assist enzymes with energy release Thiamin (Vitamin B1) o Part of coenzyme thiamin pyrophosphate (TPP) o Assists in energy metabolism Conversion of pyruvate to acetyl choline TCA cycle o Nerve activity and muscle activity o Beriberimalnourished and alcoholics (80%) are deficient o Destroyed by heat Riboflavin (Vitamin B2) o Serves as coenzyme in energy metabolism Flavin mononucleotide (FMN) Flavin adenine dinucleotide (FAD) o Sources: pork and milk products o Destroyed by ultraviolet light and radiation Niacin (Vitamin B3) o Two structures: nicotinic acid and nicotinamide (blood) o Two coenzyme forms metabolic reactions Nicotinamide adenine dinucleotide (NAD) Carries hydrogens and electrons NADP (phosphate form) o Deficiency Pellagra Four D’s: diarrhea, dermatitis, dementia, death o Health Benefits Nicotinic acid lowers cholesterol and triglycerides, raises HDL cholesterol and protects against heart disease o Sources: meat, fish, poultry, potatoes Vitamin B6 o Three forms: pyridoxal, pyridoxine, pyridoxamine o Conversion to coenzyme PLP Amino acid metabolism Conversion of tryptophan to niacin or serotonin o Stored exclusively in muscle tissue o Deficiency causes depression and confusion Alcohol causes destruction and loss o More than 2g/day can cause neurological damage (20x upper level of 100mg) Folate o Folic acid (most stable form) o Primary coenzyme form tetrahydrofolate (THF) Converts vitamin B12 to coenzyme form Synthesizes DNA o Bioavailability 50100% o Increased need during pregnancy o GI tract injuries hinder absorption of folate o Deficiency: Neural tube defects: supplement used before and during first trimester for spinal cord development Protects against heart disease by breaking down homocysteine Anemia Destroyed by heat and oxidation o Fortified foods and supplements caused toxicity Vitamin B12 (Cobalamin) o Vitamin B12 and folate activate each other o Synthesis of DNA and RNA o Hydrochloric acid releases B12 Intrinsic factor: as food leaves the stomach, it binds with B12 to aid in absorption o Deficiency common among elderly o Helps convert folate to folic acid o Sources: almost exclusively animal products (fish and milk) o Destroyed by microwave Each B vitamin coenzyme is involved in energy metabolism Excess of B vitamins is eliminated through urine Vitamin C o Defends against free radicals o Protects tissues from oxidative stress (antioxidant) o Prevents heart disease and cataract formation o ADRENAL GLAND contains most vitamin C, releases vitamin C and hormones into blood o Vitamin C deficiency: 10 mg prevents scurvy, 200mg is absorption maximum Bleeding gums, broken capillaries o Supplements cause diarrhea and GI distress o Sources: fruits, vegetables (potatoes) o Destroyed by heat and oxygen Vitamin A o *Precursor: betacarotene o Forms: retinol, retinal, retinoic acid Retinol: supports reproduction, major transport and storage Betacarotene split into retinol in liver and intestines Retinolbinding protein takes vitamin A from liver to blood *Retinal: active in vision Retinoic acid: regulates cell differentiation, growth and embryonic development Liver stores 90% of vitamin A Toxicity: preformed vitamin A from animals, fortified foods and supplements Recommendations expressed in retinol activity equivalents (RAE) Supplements measured in international units (IU) Vitamin D o D2 from plants (ergocalciferol) o D3 from animals (cholecalciferol) o Enhances calcium and phosphorous absorption o Deficiency: Rickets o Sources: oily fish, egg yolks, fortified milk Vitamin E o Antioxidant o Deficiency: red blood cells burst Erythrocyte hemolysis o Toxicity: may interfere with vitamin K o Destroyed by heat and oxidation Vitamin K o Blood clotting o Deficiency is rare o Single dose given to infants at birth o Synthesized by bacteria in GI tract RDAs o Established for thiamin, riboflavin, niacin, folate, vitamin B6, B12 and vitamin C o Only niacin, folate, vitamin B6 and vitamin C have upper intake level Water and Minerals Water o Lean tissue is 75% water o Functions of water: Carries nutrients and waste products Serves as a solvent Acts as lubricant and cushion Aids in regulation of body temperature Maintains blood volume o Intracellular fluid: inside cells o Dehydration: thirst, fatigue, weakness, exhaustion, delirium, death o Food sources: Fruits and vegetables 90% Meats and cheese 50% o Need at least 500mL of water to carry away waste o Lose 2500mL daily o Recommendation: 23 liters (812 cups) per day o Types of Water: Hard high concentration of calcium and magnesium Soft principle mineral is sodium OR potassium Blood Volume and Blood Pressure o Regulated by kidneys o Antidiuretic hormone (ADH) is waterconserving hormone Stimulates kidneys to reabsorb water Renin o Enzyme released by kidneys when blood pressure is low Stimulates kidneys to reabsorb sodium Hydrolyzes angiotensinogen to angiotensin I Inactive until angiotensin II Fluid Balance o 2/3 inside cells Too much causes rupture o 1/3 outside cells Too much causes collapse o Dissociation of salt Sodium cation (+) Chloride anion () Electrolyte Balance o Predominantly outside cell: sodium, chloride, calcium o Predominantly inside cell: potassium, magnesium, phosphate, sulfate Fluid and Electrolyte Imbalance o Vomiting or diarrhea= sodium loss o Tumor development= potassium loss o Blood pH Below 6.8= acidosis Above 8.0= alkalosis o Oral Rehydration Therapy used to replace lost fluids and electrolytes due to diarrhea Plain cool water and regular foods Sugar, salt and water Buffers o Bicarbonate: base Slows down respiration o Carbonic acid: acid Speeds up respiration Sodium o Principle cation of extracellular fluid o Travels freely in blood o Kidneys filter out and return what is needed o 40% sodium, 60% chloride o Upper limit: 2300 mg 1500 for African Americans Average intake 3400 mg o Sodium and chloride have an interaction o DASH Diet Dietary Approaches to Stop Hypertension o Processed foods account for 75% of salt intake o Deficiency: hyponatremia o Toxicity: edema, high blood pressure, hypertension Potassium o Principal intracellular cation o Roles: Maintains fluid and electrolyte balance Maintains cell integrity Aids in nerve impulse transmission and muscle contraction *Low potassium= muscle weakness Can stop heart if injected into vein Calcium o Most abundant mineral in body o 99% in bones and teeth o Recommendations accommodate 30% average absorption rate 1300 mg per day for adolescents 1000 mg per day for adults up to 50 1200 mg per day for women over 50 and men over 70 o Peak bone mass in late 20s o Osteopenia=low bone mass Osteoporosis and Calcium o Cortical and trabecular bone o Up to 20% bone loss 68 years after menopause
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'