HS 331: Chapter 5-8 Exam Material
HS 331: Chapter 5-8 Exam Material HS 331
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This 9 page Study Guide was uploaded by Sydney Brummett on Sunday October 16, 2016. The Study Guide belongs to HS 331 at Wichita State University taught by Dr. Lisa Wray in Fall 2016. Since its upload, it has received 88 views. For similar materials see Principles of Diet and Nutrition in Health Sciences at Wichita State University.
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Date Created: 10/16/16
Exam 2 Study Guide: Covering: Fats, Proteins, Nutrients Involved in Fluid and Electrolyte Balance, and Nutrients Involved in Antioxidant Function and Vision (Ch. 5-8) Chapter 5 Main Points: • What are fats? o Lipids: diverse class of organic substances that are insoluble in water • Triglycerides o Triglycerides are composed of § Three fatty acid molecules • Fatty acids: long chains of carbon atoms surrounded by hydrogen atoms § One glycerol molecule • Glycerol: a three-carbon alcohol that is the backbone of a triglyceride o Saturated fatty acids have hydrogen atoms surrounding every carbon in the chain; they have no double bonds o Monounsaturated fatty acids lack hydrogen atoms in one region; they have one double bond o Polyunsaturated fatty acids lack hydrogen atoms in multiple locations; they have two or more double bonds o Note: each double bond causes the loss of two hydrogen atoms o The shape of a triglyceride is determined by the saturation of the carbon chains o The hydrogen atoms at the unsaturated region can be arranged in different positions § Cis: same side of the carbon chain § Trans: opposite sides of the carbon chain. o Hydrogenation: the addition of hydrogen atoms to unsaturated fatty acids § Converts liquid fats (oils) into a semisolid (spreadable) or solid form § Used to create margarine from plant oil § Often creates trans fatty acids § Listed on food labels as partially hydrogenated oil • Essential Fatty Acids o Essential fatty acids cannot be synthesized in the body and must be obtained in the diet § Omega-6 and omega-3 fatty acids § They are precursors to biological compounds called eicosanoids, which regulate cellular function o Linoleic acid is found in veggies and nut oils o Alpha-linolenic acid (ALA) is derived from dark-green leafy veggies, flaxseeds and flaxseed oil, soybeans and soybean oil, walnuts and walnut oil, and canola oil o Eicosapentaenoic Acid (EPA) and docosahexaenoic acid (DHA) have important health benefits and are found in fish, shellfish, and fish oils • Phospholipids o Phospholipids: § Composed of • Glycerol backbone • Two fatty acids • Phosphate § Soluble in water § Manufactured in our bodies so they are not required in our diet § Important components of cell membranes • Sterols o Sterols: lipids containing multiple rings of carbon atoms § Essential components of cell membranes and many hormones § Manufactured in our bodies and therefore not an essential component of our diet § Cholesterol is the major sterol found in the body • Why do we need fats: o Fat-soluble vitamins § Vitamins A, D, E and K are soluble in fat; fat is required for their transport • How does tour body process fats? o As fat enters the small intestine: § Bile is secreted from the gallbladder into the small intestine § Bile is produced by the liver and stored in the gallbladder § Bile disperses fat into smaller fat droplets § Pancreatic enzymes break triglycerides into two separate fatty acids and a monoglyceride § Fat enters the mucosal cell as a micelle (fatty acids, monoglyceride, phospholipids, and sterols) o In the intestinal mucosal cell: § Fatty acids are reattached to the monoglyceride to re-form triglycerides § A small amount of protein is added to the lipids, forming a chylomicron § Chylomicron: a lipoprotein produced by cells lining the small intestine • Composed of triglycerides surrounded by phospholipids and proteins • Soluble in water § Chylomicrons are the transport vehicles that remove absorbed fats from the small intestine • Travel through the lymphatic system • Are transferred to the bloodstream § Short and medium-chain fatty acids are absorbed more quickly because they are not arranged into chylomicrons § One the chylomicron gets to a cell in the body, the triglycerides in the chylomicrons must be disassembled by lipoprotein lipase into two fatty acids and a monoglyceride before they can pass through the cell membrane § After entering the cell, the two fatty acids and monoglyceride re-form a triglyceride § The triglyceride can be: • Used immediately for energy • Used to make lipid-containing compounds • Stored in liver and muscle cells • Recognize the Fat in Foods o Visible fats are those we can see in foods or can easily see have been added to foods, such as dressing or chicken skin o Hidden fats are those added to processed or prepared foods to improve texture or taste, which may not be aware of, or that occur naturally • In depth: Cardiovascular Disease o Cardiovascular disease (CVD) § Dysfunction of the heart or blood vessels § The most common forms: • Coronary heart disease, or coronary artery disease • Stroke • Hypertension, or high blood pressure • Peripheral vascular disease o Atherosclerosis is a disease in which artery walls build up lipid deposits and scar tissue, impairing blood flow § The stiffness that results is commonly called “hardening of the arteries” § The result is that the heart must work harder to push blood through the vessels o Hypertension is a major chronic disease in the US o It functions as a warning sign for a person’s risk for developing heart disease or stroke o For many people, hypertension is hereditary; for others, it can be induced through poor nutrition and exercise habits or a combination of poor habits and heredity o Diets high in saturated fats § Decrease the removal of LDLs from the blood § Contribute to formation of plaques that can block arteries § Increase triglyceride levels (chylomicrons and very-low- density lipoproteins, or VLDLs) Chapter 6 Main Points: • What are proteins? o Proteins § Large, complex molecules found in the cells of all living things § Critical components of all the tissues of the human body § Functions in metabolism, immunity, fluid valance, and nutrient transport § In certain circumstances, provide energy § Contain a special form of nitrogen our bodies can readily use • Amino acids o Amino acids are the nitrogen-containing molecules that combine to form proteins • How are proteins made? o When two amino acids join together in a peptide bond, they form a dipeptide o Ten or more amino acids bonded together form a polypeptide o Proteins are made by combining multiple amino acids o Transcription: use of the genetic information in DNA to make RNA § mRNA copies the genetic information and carries it to the ribosome o Translation: conversion of genetic information in RNA to assemble amino acids in the proper sequence to synthesize a protein on the ribosome • Protein synthesis can be limited o Incomplete protein: does not contain all essential amino acids in sufficient quantities § Growth and health are compromised § Considered a “low-quality” protein o Complete protein: contains sufficient amounts of all nine essential amino acids § Considered a “high-quality” protein • Protein synthesis can be enhanced o Mutual supplementation: combining two incomplete proteins to make a complete protein o Complementary proteins: two protein sources that together supply all nine essential amino acids § Example: beans and rice • Can vegetarian diets provide protein? o Vegetarianism: restricting the diet to foods of plant origin § There are many versions of vegetarianism § There are many reasons to adopt a vegetarian diet • Disorders related to protein in take o Protein-energy malnutrition: a disorder caused by inadequate intake of protein and energy o There are two common, serious forms: § Marasmus § Kwashiorkor o Marasmus: disease resulting from severely inadequate intakes of protein, energy, and other nutrients § It is characterized by extreme tissue wasting and stunted growth and development o Kwashiorkor: disease resulting from extremely low protein intake § Symptoms include: • Some weight loss and muscle wasting • Edema resulting in distention of the belly • Retarded growth and development § Often seen in children in developing countries • Disorder related to Genetic abnormalities o Phenylketonuria (PKU) is a disorder in which a person does not have the ability to break down the amino acid phenylalanine o Sickle cell anemia causes red blood cells to be shaped in a way that impedes their transport to body tissues o Cystic fibrosis causes an alteration in chloride transport, leading to a sticky mucus that causes life-threatening respiratory and digestive problems • In depth: Vitamins and Minerals o Characteristics of fat-soluble vitamins § Large storage capability § Toxicity is possible § Deficiency symptoms may take many months to develop § May occur in numerous chemical forms o Characteristic of major minerals § Required in amounts of at least 100 mg/day § Body contains 5 g or higher § Seven major minerals o Characteristics of trace minerals § Required in amounts of less than 100 mg/day § Body contains less than 5 g § Eight trace minerals are essential for human health Chapter 7 Main Points: • Fluids o Substances composed of freely moving molecules o Have the ability to conform the shape of the container that holds them o There are different types of fluids in our bodies § Two-thirds of the body’s fluid is intracellular fluid • In the cell § The remaining one-third is extracellular fluid • Outside the cell o Extracellular fluids include: § Tissue fluid, found between the cells within tissues and organs of the body § Plasma: the fluid portion of blood that carries the blood cells o The body fluid composition of tissue varies by: § Tissue type – lean tissues have higher fluid content than fat tissues § Gender – makes have more lean tissue and therefore more body fluid § Age – lean tissue is lost with age, and body fluid is lost with it. • Functions of Fluids o Fluids dissolve and transport substances § Water is an excellent solvent because it can dissolve many different substances § The dissolved materials, or solutes, include ions, carbs, amino acids, vitamins, and minerals • Maintaining fluid balance o Fluid balance is maintained by different mechanisms prompting us to drink and retain fluid o The thirst mechanism occurs from a cluster of nerve cells that stimulate our desire to drink o However, the thirst mechanism is not always sufficient; the amount of fluids people drink may not be enough to achieve fluid balance o Water lost from the body must be replaced o Water is lost through urine, sweat, evaporation, exhalation, and feces o Water is gained through beverages, food and metabolic reactions § Metabolic water contributes about 10-14% of the water the body needs o Loss of water § Sensible water loss occurs though urine and sweat • Most water is lost through urine • The kidneys control how much water is reabsorbed; excess water is processed by the kidneys and excreted as urine § Insensible water loss occurs through evaporation from the skin or exhalation from the lugs, as well as through feces o Diuretic increase fluid loss via the urine • Sodium o What if you consume too much sodium? § Hypernatremia: abnormally high blood sodium concentration § Can occur in patients with congestive heart failure or kidney disease § Results in high blood volume, edema, and high blood pressure o What if you don’t consume enough sodium? § Hyponatremia: an abnormally low blood sodium level § Can result from prolonged vomiting, diarrhea, or sweating § Has been seen in marathon athletes who consume too much water and fail to replace sodium • Potassium o What if you consume too much potassium? § Hyperkalemia: a high blood potassium level § Can occur in patients with kidney disease § Can alter normal heart rhythm, resulting in a heart attack o What if you don’t’ consume enough potassium? § Hypokalemia: a low blood potassium level § Can be seen in patients with kidney disease or diabetic acidosis § Can occur when taking certain diuretic medications • Dehydration o Dehydration occurs when water loss exceeds water intake § Commonly due to heavy exercise or high environmental temperatures § Infants and the elderly are more at risk • Heatstroke o Heatstroke occurs if the body’s temperature regulation mechanisms fail § Occurs in hot, humid environments § Symptoms include rapid pulse, hot and dry din, high body temperature, and weakness § Has been fatal for athletes during exercise in extreme heat § If it occurs, provide immediate cooling and rest, and contact emergency medical help quickly • In Depth: Alcohol o What is moderate alcohol intake? § A drink is defined as the amount of a beverage that provides ½ fluid ounce of pure alcohol § Proof is a measurement of alcohol content § Moderate alcohol intake is defined as the consumption of up to one drink per day for women, and up to two drinks per day for men o Types of alcohol abuse: § Alcohol abuse is excessive intake of alcohol § Binge drinking is consumption of five or more drinks per occasion § Alcoholism is a disease characterized by chronic dependence on alcohol o Effects of alcohol abuse: § A hangover is a consequence of drinking too much alcohol; symptoms include headache, fatigue, dizziness, muscle aches, and nausea § Even at low intakes, alcohol impairs reasoning and judgment § Alcohol poisoning is a potentially fatal metabolic state involving cardiac and respiratory failure § Alcohol abuse can lead to traumatic injury from falls, drowning, assaults, and traffic accidents § When the rate of alcohol intake exceeds the ability of the liver to break alcohol down, liver cells are damaged or destroyed • Fatty liver is an early but reversible sign of liver damage • Alcohol hepatitis results in loss of appetite, nausea and vomiting, abdominal pain and jaundice • Cirrhosis of the liver involves permanent scarring after years of alcohol abuse § Chronically high intake increases risk for: • Impaired bone health • Pancreatic injury and diabetes • Cancer • Abdominal obesity • Malnutrition o Fetal and infant health problems include: § Fetal alcohol syndrome (FAS), a set of serious, irreversible birth defects, including physical, emotional, behavioral, and developmental problems § Fetal alcohol effects (FAE), subtler consequences that may be exhibited later, including hyperactivity, attention deficit disorder, and impaired learning abilities Chapter 8 Main Points: • Structure of Atoms o Atom: the smallest unit of matter § Atoms are composed of • Nucleus – positively charged center portion of the atom • Electrons – negatively charged particles surrounding the nucleus • Oxidation: o Oxidation: the loss of electrons from a molecule o Reduction: the gain of electrons by a molecule o Free radical: an atom that has lost an electron and is left with an unpaired electron • Vitamin C: o Functions of vitamin C: § Antioxidant § Synthesis of collagen § Prevents the disease scurvy § Enhances the immune system § Regenerated vitamin E after oxidation § Enhances the absorption of iron o What if you consume too much Vitamin C? § Megadoses (10 times or more of the recommended intake) of vitamin C can cause nausea, diarrhea, nosebleeds, and abdominal cramps • Selenium o What if you don’t consume enough? § Keshan disease: a form of heart disease § Kashin-Beck disease: a type of arthritis • Copper, Iron, Zinc and Manganese o Cofactor: a compound needed for proper functioning an enzyme § Are cofactors for the superoxide dismutase antioxidant enzyme system § Help us maintain the health of our blood • Beta-Carotene: o Beta-carotene is: § In the class of chemicals called carotenoids § A provitamin: inactive precursors that must be converted to the active form of a vitamin in the body § The precursor or retinol, an active form of vitamin A • Vitamin A o There are 3 active forms of vitamin A: § Retinol § Retinal § Retinoic Acid • In Depth: Cancer o Cancer: a group of related diseases characterized by cells growing out of control § Initiation – a cell’s DNA is mutated § Promotion – altered cell repeatedly divides § Progression – cells grow out of control