Final Exam Review HNSC 1210 Unit 5 Definitions: Hydrogenation: process where hydrogen is added to unsaturated fatty acids, to make a more solid fat (e.g. turning vegetable oil into hard margarine) Artheroschlerosis: underling cause of heart attacks and strokes Lipoproteins: serve to move lipids in blood and lymph Chylomicrons: clusters formed when dietary lipids combine with carrier proteins in the intestinal tract Very low density lipoprotein (VLDL): transport triglycerides and other lipids from the liver to various tissues in the body for use Low density lipoprotein (LDL): transport cholesterol from the liver to other tisssues. LDL are made from VLDL. Larger, lighter, and richer in cholesterol High density lipoprotein: are critical in the process of carrying cholesterol away from body cells to the liver for disposal. Smaller, denser, and packed with more protein Ketones: products of incomplete fat breakdown - Fat (DRI = 20-35% energy from dietary fat; <10% energy from saturated fat): - Allows us to survive during a famine - Secretes hormones that help regulate appetite and influence other body functions - Functions in body: pads vital internal organs, and can be converted into other compounds (e.g. hormones, bile, Vitamin D) - Functions in food: provides essential nutrients, concentrated source of energy & raw materials for making needed products, provides taste, smell, and tender texture, stimulates appetite and feelings of fullness - Saturated (e.g. beef, pork, cream, etc.) and trans-fat (e.g. cookies, crackers, etc.) intake raises cholesterol - Unsaturated fat (e.g. avocado, nuts, etc.) reduces blood clotting - Polyunsaturated fatty acids DRI: 5-10% energy from linoleic acid (omega-6) and 0.6-1.2 from linolenic acid (omega-3) - Classifications of lipids: triglycerids, phospholipids, and sterols - Triglycerides: - Very few found free in body - Glycerol is an organic compound 3-carbons long - Fats in the diet can affect the type of triglyceridses made because dietary fats are incorporated into triglycerides in the body - Fatty acids are classified by: a. Chain length: Short: <10 carbons Medium: 12-14 carbons Long: >16 carbons NOTE: shorter fatty acids tend to be softer and melt more readily at room temp b. Degree of saturation (double bonds, C=C) Saturation refers to the number of hydrogen atoms a fatty chain is holding The most hydrogen atoms attached, the more saturated the fatty acid is When no hydrogen is attached, this is a point of unsaturation, and a double bond occurs (e.g. in the fatty acids of plants and fish) The more saturated the fat, the more liquid it tends to be at room temperature (e.g. animal fats are generally the most saturated and hardest) - Saturated fatty acid: no points of unsaturation, ten to be soft at room temp, animal fats (e.g. butter, lard), tropical oils (e.g. coconut oil, palm oil). Can increase “bad” blood cholesterol level (LDL) - Monosaturated fatty acid (MUFA): one pont of unsaturation, vegetable oils - Effects of processing on unsaturated fats: - Hydrogenation on Margarine: hydrogen attaches at the point of unsaturation (double bond), and the fatty acid becomes saturated. This makes the fatty acid more solid at room temperature and increases shelf life. Points of unsaturation are more vulnerable to oxidation therefore hydrogenated fats are more resistant to oxidation. Have a higher smoking point. Once hydrogenated, the unsaturated fats lose their health benefits. Problems: Affects fatty acids as well as vitamins Decreases activity of Viramin K in body Some change shape instead of becoming saturated (trans fatty acids) Trans fatty acids post a risk to hearth health by raining LDL and lowering HDL. They also product inflammation - Blending different oils to product a “soft margarine”: used to avoid creating trans fatty acids, creates soft, nonhydrogenated margarine (e.g. Becel), product will not remain solid at room temperature as the fats are unsaturated - Phospholipids: - Glycerol backbone + 2 fatty acids + 2 phosphorus containing molecules - Water and fat soluble - Can serve as an emulsifier - Example: Leithin (phospholipid in egg yolk, non-essential) - Can play a key role in the structure of cell membranes - Sterols: - Large molecules consisting of interconnecting rings of carbon atoms, with side chains of carbon, hydrogen, and oxygen - Example: cholesterol (important in the structure of cell membranes, not essential) - Benefits of cholesterol: Necessary to make bile (important in fat digestion) Necessary to make Vitamin D 1 Necessary to make sex hormones Necessary to make stress hormones - Bad about cholesterol: Forms the major part of the plaques that narrow the ateries in atherosclerosis - Lipid Digestion and Absorption: - In the stomach: Once fat enters stomach, it separates from the water chyme and floats on top of it Little fat digestion occurs in the stomach - In the small intestine: Bile works to emulsify the fat with watery digestive fluids because one end attracts and holds fat, while the other end is attracted and held by water By the time the fat has entered the small intestine, the gallbladder has already contracted and squirted the stored bile into the intestine (note: if a person has their gallbladder removed, their liver will still produce bile however, their system can only handle small amounts of fat at a time) The bile emulsifies and suspents the fat particles so that fat-digesting enzymes from the pancreas can split them into small particles for absorption Once the intestinal contents are emulsified, fat-splitting enzymes work on triglycerides to free the fatty acids from the glycerol backbone The free fatty acids, glycerol, and monoglycerides cling together in balls surrounded by bile The bile helps to move the fats across the watery layer of mucus that coats the absorptive lining at the digestive tract - At the lining of the digestive tract: Small lipid particles enter directly into the capillary network and travel unassisted to the liver Large lipid molecules are re-formed into triglycerides in the intestinal cells and are packaged together with proteins and phospholipids to form chylomicrons, which can safely travel in the watery blood - Lipid Metabolism: - Fatty acids are used for energy by many organs: typical fuel mix at rest is 50/50 carbohydrate/lipid for liver and muscle - Anytime fat is broken down for energy, carbohydrate must be available otherwise ketones develop and build up in blood and urine - Cholesterol: - Important sterol in the structure of brain and nerve cells - About 75-80% is synthesized in the body (de novo) - ~ 60% exhibit little increase in blood cholesterol with high cholesterol diet - Many foods that are higher in dietary cholesterol are also nutritious - Atheroschlerosis: - Most common heart disease (develops early in life = age 30) - Plaque development along artery walls - Starts with accumulation of soft fatty streaks. These gradually enlarge and harden to form plaque - Plaque damages the artery walls by narrowing the passage through them and making them inelastic - Major contributer: diet high in saturated fat - Develops through a complex inflammatory response to tissue damage: 1) WBC’s are sent to site of damage 2) LDL particles become trapped in blood vessel walls 3) Free radicals oxidize the LDL 4) Macrophages engulf LDL and become foam cells (= filled with lipid) 5) Muscle cells in artery walls proliferate and try to heal damage 6) Muscle cells combine with foam cells 7) Fibrous plaques form (scar tissue) - Ways to increase HDL: - Maintain healthy body weight - Engage in regular physical activity - Quit smoking - Ways to lower LDL: - Maintain healthy body weight - Increase intake of soluble fiber - Reduce intake of saturated and trans fat - Omega-6 Fatty Acids: - Double carbon bond 6 cabons from the end of its chain - E.g. linoleic acid - DRI Recommendation: 5-10% energy from n-6 fatty acids - Sources: vegetable oils, seeds, nuts, whole grain products - Omega-3 Fatty Acids: - Double carbon bond with 3 carbons from the end of its chain - E.g. Linolenic acid - DRI Recommendation: 0.6-1.2% energy from n-3 fatty acids - Sources: flaxseed, canola oil, fish - 3 main types: ALA (plant sources), EPA (fish sources), DHA (fish sources) - It is recommended you eat 2 fish meals per week (150 g per week) (to help decrease heart disease, infant growth and development, and decrease cancer) - Fish oil supplements may raise LDL cholesterol - Pregnant women: limit intake of larger fish to 150 g per month and intake of canned tuna to no more than 300 g per week - Children (5-11) limit intake of fish to 125 g per month and canned tuna to no more than 150 g per week - Young children (1-4) limit intake to no more than 75 g per month and canned tuna to 75 g per week - Traditional Mediterranean diets are: - High in total fat - Low in saturated fat - Very low in trans fat 2 Unit 6 - Rich in unsaturated fat Rich in complex carbohydrates and fiber Rich in nutrients and phytochemcials that suppor goof health Low in animal protein and fat Definitions: Sickle cell disease: condition where the hemoglobin is abnormally shaped and therefore loses its function to carry and release oxygen. This is because one of the protein strands contains Valine as the 6 th amino acid instead of glutamc acid. If too many crescent shaped cells appear in the blood, abnormal blood clotting, strokes, susceptibility to infection, severe pan, and early death can occur Positive nitrogen balance: nitrogen in exceeds nitrogen out. Somewhere in their bodies, more protein is being build than are being broken down (e.g. children and pregnant women) Negative protein balance: nitrogen out exceeds nitrogen in. Muscle or other protein tissues is being broken down and lost (e.g. illness, injury, astronauts) Lacto-ovo vegetarian: includes dairy products, eggs, and all other foods in vegan diet Lacto vegetarian: includes daity products and allo ther foods in vegan diet Oco vegetarian: includes eggs and all other foods in vegan diet Pesco vegetarian: same as partial vegetarian (includes seafood, eggs, etc.) but eliminates poultry Fruitarian: includes only raw or dried fruits, seeds and nuts in the diet Macrobiotic diet: vegan diet composed mostly of whole grains, etc. Does not normally contain vitamins - Proteins and amino acids: - Protein recommendations: DRI: 0.8g/kg body weight (woman: 46 g/day; man: 56g/day) - AMDR: 10-35% total energy - Proteins are made up of CHON - Working proteins: enzymes, antibodies, hormones, oxygen carriers, etc. - Structural proteins: tendons, ligaments, fibers of muscles, found in our bones, teeth, hair, and nails - Amino acids are the building blocks of proteins (a protein strand can have 20 different amino acids) - All amino acids have the same chemical backbone: a single carbon atom, with an amine group, ad an acid group attached - About 20 amino acids make up most of the proteins of living tissues (amino acids are joined by peptide bonds to make proteins) - Essential amino acids: Tryptophan, Valine, Threonine, Isoleucine, Leucine, Lysine, Phenylalanine, Methionine - The body can recycle amino acids by breaking apart food proteins after digestion. This allows for an emergency supply of amino acids - Protein Synthesis: - A single human cell can contrin as many as 10,000 different proteins - Our genes determine the sequence of amino acids in each finished protein. Different sequences account for genetic disease (e.g. Sickle Cell Disease) - Protein Digestion: - When a person eats proteins, the body must alter them by breaking them down into amino acids. Then it can rearrange them into specific body proteins - Starts in the STOMACH - Gastric acid denatures the protein, opening it up to allow the digestive enzymes to break the peptide bonds - By the time most enter the small intestine, they are broken down into smaller pieces - Protein digesting enzymes from the pancrease and intestine split the polypeptides into di and tripeptides and amino acids - Enzymes on the surface of the lining of the small intestine split the peptides, allowing the intestinal cells to absorb and transfer them into the bloodstream - Once in the bloodstream, the amino acids re transported to all of the body’s cells - Sometimes larger peptide molecules escape the digestive process. It is thought that these larger molecules may act as hormones to regulate body functions. They may also stimulate an immune response, thus playing a role in food allergies - Protein Absorption: - Amino acids of the same compete for the same absorptive site therefore consuming a large dose of one amino acid may limit the absorption of other amino acids of the same general type - Once the amino acids are in the bloodstream, they travel to the liver where they are used or released back into the blood to be taken up by other body cells - Functions of Proteins: 1) Suporting growth and maintenance 2) Building enzymes, hormones, and other compounds 3) Building antibodies 4) Maintaining fluid and electrolyte balance 5) Maintaining acid-base balance 6) Clotting of the blood 7) Providing energy and glucose - Protein Utilization: - When amino acids arrive at a cell, it can be used in one of the several ways: 1) To build part of a growing protein 2) Altered to make another needed compound 3) The cell can dismantle the amino acid in order to use the amine group to build a different amino acid. The remainder can be used for energy or converted into glucose or fat for storage. Excess will be excreted in the urine - Amino acids are considered wasted when they are not used to build protein. This occurs when any of these conditions exist: 1) When the body does not have enough energy from other sources 2) When the diet provides more protein than the body needs 3) When the diet has too much of any single amino acid 3 4) When the diet supplies protein of low quality, with too fe essential amino acids - To prevent wasting, dietary protein must be: 1) Adequate in quantity 2) Supply all essential amino acids in the proper amounts 3) Must be accompanied by adequate energy from CHO and fat - Protein in Food: - Most in meat and alternatives - Milk and alternatives contribute an abundance of high-quality of protein - Vegetables and fruit also contribute smaller amounts - Animal protein is most easily digested and absorbed - Cooking with moist heat improves protein digestibility, where as dry heat can impair it - Protein Energy Malnutrition: - Worlds most widespread form of malnutrition - Strikes early in childhood causing stunted growth, however affects adults as well - Two forms: 1) Marasmus: slow, chronic form of PEM. Seen in children 6-18 months. Malabsorption occurs because digestive enzyme are short in supply and digestive tract lining deteriorates. Children suffer severe weight loss, including muscle and fat loss. Muscles weaken and brain development is stunted. Hair becomes sparse, thin, dry, and pulls out easily. Skin becomes dry and wrinkled. An infection of the digestive tract is when diarrhea can occur. The rate of incrections increases and Kwashiorkor often follows because the body is using more protein to try to fight infection 2) Kwashiorkor: severe, acute malnutrition with too little protein to support body function. Seen in children ages 1-3. The frist baby is weaned from breast milk as soon as the second is born. The hair becomes dry, brittle, and easy to pull out but can also change color and straighten. Skin becomes scaly and patchy with lesions that fail to heal. Wasting of the body fat or muscles not seen so the body do not look wasted. Edema occurs and the belly often protrudes because of fatty liver - Protein Excess: - DRI recommends no more than 35% of total calories come from protein - High intakes are often associated with: obesity, increased saturated fat intake, kidney/liver problems, bone mineral loss Unit 7 Definitions: Gene expression: regulates activities of genes, which direct the synthesis of proteins - Fat Soluble Vitamins (A, D, E, K) - Dissolve in lipid and require bile for absorption - Absorbed into lymph and travel through the blood with protein carriers - Can be stored in the liver or with other lipids in fatty tissues - Can build up to toxic levels - Vitamin A - First fat-soluble vitamin recognized in the body - Three active forms: 1) Retinol is stored in the liver and the body’s cells convert it to two other active forms 2) Retinal 3) Retinolic acid - B-Carontene can be converted to Vitamin A (precursor). It takes about 12 ug B-carotene to supply 1 ug of retinol - B-Carotene is an antioxidant - Functions: 1) Gene expression 2) Vision (if vitamin A is deficient, night blindness can occur (keratinization). If this continues, the whole cornea will dry out and cause permanent blindness (xeropthalmia)) 3) Maintenance of the epithelial tissue 4) Immune defences 5) Growth of bones (important in dismantling process) 6) Reproduction - Toxicity: - Natural source = liver - Can weaken bones - High doses can cause malformations in fetus - Symptoms: stunted growth, muscle/bone pain, edema, fatigue, blurred vision, headaches, loss of menstruation, abdonminal pain, anorexia, nausea, diarrhea, skin disorders, hair loss, liver damage, enlarged spleen - Forms: 1) Retin-A: used for acne 2) Renova: used as an anti-wrinkle product 3) All are highly toxic and at risk for causing birth defects if taken while pregnant - Vitamin D (cholecalciferol) - Functions: 1) Regulating blood calcium and phosphorus levels 2) Maintaining bone integrity 3) Functions as hormones and plays roles in workings of the brain, heart, stomach, pancreas, skin, cells of immune system, and reproductive organs - Food sources: fortified milk and margarine, eggs, butter, fish, etc. - UV light from the sun converts a cholesterol compound in human skin into a vitamin D precursor - Fair skin needs about 10-15 mins a day 3-7 days a week - Dark skin may need about 3 hours 4 - In Manitoba, we only have the strength of the sun in summer. In winter months, we rely on our liver stores - Deficiency: 1) Rickets (children): bowed legs because the bones become too weak to support body weight. May also develop knobs on ribs 2) Osteomalacia (adults): can occur inwomen with repeated pregnancies who have low calcium intake, little sun exposure, and breastfeed multiple children 5
- Я же угада… - Но она замолкла на полуслове. На ее пальце было не кольцо Танкадо. Это было другое кольцо - платиновое, с крупным сверкающим бриллиантом. Сьюзан охнула. Дэвид посмотрел ей в глаза: - Ты выйдешь за меня замуж.