HS201 Exam One Notes

Chapter 1 Nutrition: how nutrients and compounds in foods nourish and affect body functions and health Nutrients: essential chemicals in food that support human life; must come from diet 1. Carbohydrate (Macronutrients) o CHO; major source of fuel; starches and sugars; o Found in grains, veggies, legumes, fruits, dairy products o Body converts dietary CHO to blood sugar or glucose 2. Protein (Macronutrients) o CHON o Build and maintain body structure o Making hormones, enzymes, healthy immune system o Found in foods from animals, dairy foods, veggies, grains 3. Fat (organic) (Macronutrients) o CHO; provide structure for body cells o Carry fat-soluble vitamins A, D, E, K o Provide starting material for many hormones o Found in fats and oils, meats, coconut, olives, avocado 4. Vitamins (organic) (Micronutrients) o Regulate body processes, keep organs and tissues functioning o Essential for metabolism; many assist enzymes in speeding up chemical reactions o Fat-soluble and water-soluble 5. Minerals (inorganic) (Micronutrients) o Essential for metabolism; many assist enzymes in speeding up chemical reactions o Deficiencies are uncommon, except calcium and iron o Body processes and structures 6. Water (inorganic) o Helps chemical reactions o Transporting nutrients and oxygen to cells and removing waste products o Lubricant for joints, eyes, mouth, intestinal tract o Protective cushion for organs o Temperature control, lubrication of joints, transport of nutrients and wastes 7. (Alcohol) Nutrients Micronutrients Macronutrients Water Protein* Vitamins Minerals Fat* Carbohydrate* Alcohol Functions:  Provide fuel or energy: calorie  Regulate body processes: metabolism  Contribute to body structures: bones, muscles, all cells  Form and maintain shape and structure The American Diet:  65% of adults and 15% of children are overweight  Heavy in meat and potatoes; light in fruits and whole grains; super sizing  High in sodium, saturated fat, calories; low in vitamin E, calcium, fiber The Arithmetic: • CHO yields 4 kcal/gram, • Protein yields 4 kcal/gram • Fat yields 9 kcal/gram • Alcohol yields 7 kcal/gram • Total Calories = (CHO (g) x 4 kcal) + (Protein (g) x 4 kcal) + (Fat (g) x 9 kcal) FDA rounding rules: Nutrient Calories Calories from Fat Calories from Saturated Fat Total Fat Saturated Fat Polyunsaturated Fat Monounsaturated Fat Sodium Potassium Protein Increment Rounding < 5 cal - express as 0 ≤ 50 cal - express to nearest 5 cal increment > 50 cal - express to nearest 10 cal increment < .5 g - express as 0 < 5 g - express to nearest .5g increment ≥ 5 g - express to nearest 1 g increment Insignificant Amount < 5 cal < .5 g < 5 mg - express as 0 < 5 mg 5 - 140 mg - express to nearest 5 mg increment > 140 mg - express to nearest 10 mg increment < .5 g - express as 0 <1g < 1 g - express as "Contains less than 1 g" or "less than 1 g" or to 1 g if .5 g to < 1 g ≥ 1 g - express to nearest 1 g increment Chapter 2 Dietary Reference Intakes, and Dietary Guidelines Malnourished: long-term outcome of consuming diet that doesn’t meet nutrient needs Tools: 1. Dietary Reference Intakes (DRIs) 1. Nutrient recommendations (maintain good health; prevent chronic diseases, avoid unhealthy excesses)  EAR (Estimated Average Requirement): average amount of a nutrient known to meet the needs of 50% of individuals of same age and gender  RDA (Recommended Dietary Allowance): meets the needs of 97-98%  AI (Adequate Intake): If insufficient scientific data; next best estimate amount  UL (Tolerable Upper Intake Level): highest amount of nutrient that won’t cause harm if consumed daily; or else, cause toxicity  AMDR (Acceptable Macronutrient Distribution Ranges): o Carbohydrates: 45-65% o Fat: 20-35% o Proteins: 10-35% 2. Dietary Guidelines for Americans  General dietary and lifestyle advice; updated every 5 years  Two concepts: i. Maintain calorie balance over time to achieve and sustain healthy weight ii. Consume more nutrient-rich foods and beverages  Key recommendations: i. Balance calories to manage weight: improved eating habits, increased physical activity  Reduce some food components: limit sodium, saturated fat, trans fat, sugars, refined grains, alcohol  Food to reduce: i. Sodium (<2300 mg or 1500 mg*) ii. Fats 1. Saturated fatty acids (<10% of calories) 2. Trans fatty acids (as low as possible) 3. Cholesterol (<300 mg) iii. Calories from solid fats and added sugars (SoFAS, 5-15%) iv. Refined grains v. Alcohol (men ≤2 drinks; women ≤1 drink per day)  Models three dietary patterns  Healthy U.S. Pattern; Healthy Mediterranean-style Pattern; Health Vegetarian Pattern 3. MyPlate  Food group recommendations  Food pyramid: 1992  MyPyramid: 2005  MyPlate: 2011  Focuses on proportionality, moderation, variety and personalization  Gives you the number of servings to eat from each food group based on your daily calorie needs  Your calorie needs are based on your age, gender, and activity level  It takes 20 mins for stomach to tell your brain you’re full 4. Nutrient Facts panel  Daily values on food labels  Food label helps consumers make informed food choices  5 mandatory components: o statement of identity: common or usual name o net contents of package o list of ingredients, in descending order by weight o information about the manufacturer o nutrition information  Nutrition Labeling and Education Act of 1990: o Uniform nutrition information and serving sizes o Health claims that are accurate and science-based o How a serving of food fits into an overall daily diet o Uniform definition for descriptive labels term such as fat-free and light  Exemptions: deli items, bakery foods, ready-to-eat foods prepared and sold in restaurants, or produced by small businesses 5. Label Claims  Whole grain food product must contain 8 grams or more of whole grain per 30 grams of product     Calcium and Osteoporosis o Claim: A diet adequate in calcium may help reduce the risk for osteoporosis, a degenerative bone disease. o Requirements: At least 200 milligrams calcium, no more phosphorus than calcium per serving, and calcium must be in a form that can be readily absorbed by the body. Fat and Cancer o Claim: A low-fat diet may help the risk for developing some types of cancer. o Requirements: 3 grams or less fat per serving or fish and game meats that are "extralean" (fewer than 5 grams fat, fewer than 2 grams saturated fat, and fewer than 95 milligrams cholesterol per serving). Fiber-Containing Fruits, Vegetables and Grain Products and Risk of CHD o Claim: Along with eating a diet low in fat, saturated fat, and cholesterol, fiber may help reduce blood cholesterol levels and the risk for developing heart disease. o Requirements: Must be or contain a fruit, vegetable or grain product, 3 grams or less fat per serving, fewer than 20 milligrams cholesterol per serving, 1 gram or less saturated fat per serving, and 15 percent or less calories from saturated fat, 0.6 grams or more dietary fiber per serving. Folate or Folic Acid and Neural Birth Defects o Claim: Healthful diets with adequate folate may reduce a woman's risk of having a child with a neural tube defect. o Requirements: The food must meet or exceed the criteria for a good source: 40 micrograms folic acid per serving or at least 10 percent of Daily Value. A serving cannot contain more than 100 percent of the Daily Value for vitamins A or D because of potential risk to fetuses.  Omega 3 - Fatty Acids o Claim: Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease. o Requirements: With the exception of fish and dietary supplements, foods must be low in cholesterol and low in saturated fat. Organic Labeling: o 100% organic = 100% organic ingredients o organic = 95% o made with organic ingredients = 70% Chapter 3 Nutrition: Digestion and Absorption Atoms and Molecules: Atoms  molecules  cells  tissues (muscle, nerve, epithelial, and connective)  organs  organ systems Organ Systems: Nervous, respiratory, urinary, reproductive, cardiovascular, lymphatic/immune, muscular, skeletal, endocrine, integumentary, digestive  Digestive: breaking down and movement of nutrients into the body o Mouthsalivary glandsesophagusliverstomachgall bladderpancreassmall intestinelarge intestinerectumanus  Endocrine: secretes chemical messengers that help regulate food intake and absorption  Nervous: sends nerve signals that help control the passage of food thru the digestive tract  Cardiovascular: transport nutrients to individual cells  Urinary, respiratory, and integumentary: elimination of metabolic waste products Digestion: breaking apart of foods into smaller and smaller  Cephalic phase: pre-absorptive responses to sensory stimulation  Chemosenses: olfactory cells; gustatory cells; common chemical sense; recognize flavors through smell Absorption: the movement of those units from the gut into the bloodstream or lymphatic system for circulation  Transit time: from mouth to anus; 24-72 hours; affected by diet, physical activity, emotions, medications, and illnesses GI tract wall  Four tissue layers 1. Mucosa: direct contact with churning food; 2-5 days; high nutrient requirements due to rapid reproduction 2. Connective tissue: contains nerve and blood vessels; support and deliver nutrient to mucosa; provides nerve signals that control secretions and muscle contractions 3. Smooth muscle layers: contraction mixes food, break into smaller particles and propels it thru the digestive tract 4. Outer connective tissue: provides support and protection Digestive Secretions  Mucus: produced by goblet cells in the mucosal lining of the gut; moistens; lubricates and protects the digestive tract  Enzymes: protein molecules that speed up chemical reactions without being consumed or changed by the reactions Regulation of Gastrointestinal Function  Hormones affects GI; are chemical messengers that are produced in one locations, released into the blood and elicit responses at other locations in the body 1. 2. 3. 4. 5. Gastrin (stomach mucosa) Somatostation (stomach and duodenal mucosa) Secretin (duodenal mucosa) Cholecystokinin (duodenal mucosa) Gastric inhibitory peptide (duodenal mucosa) The Gastrointestinal Tract (Alimentary Canal)  Connected series of organs and structures used for digestion of food and absorption of nutrients; one long tube; from mouth to rectum  Functions: ingestion; transport; secretion; absorption; movement; elimination Physical & Chemical Processes  Physical movement of food o Peristaltic contractions transport food and nutrients along the GI tract  Longitudinal muscle (propel) o Segmentation: the pushing of a mass of partially digested food (chyme)  Circular muscle (squeeze) o May move forward and backward in the small intestine  Chemical breakdown of food o Divide foods into smaller units o Digestive enzymes: catalyze the reactions that break apart nutrients; protein compounds can speed up chemical reactions; other fluids secreted into GI tract for total volume of 6-7 quarts/day Assisting Organs  Salivary glands: 3 pairs; moisten food; begins digestion; 1.5 quarts/day  Liver: produces bile (breaks up globs of fat to smaller pieces, increasing surface area and allowing fat and water to blend); detoxifies harmful substances  Gallbladder: stores bile; releases bile when stimulated by ingestion of fat; fat ingestions stimulates CCK, which causes contraction of gallbladder  Pancreas: secretes enzymes; insulin, glucagon (regulate blood sugar levels) Mouth: saliva and mucus combine with food to soften and create BOLUS; as you swallow, epiglottis closes off Esophagus: tube that connects the mouth to the stomach; peristalsis: nerve fibers release signals to increase GI muscle Stomach: can hold up to 4 cups of food; hydrochloric acid can kill bacteria; allow breakup into amino acids via enzyme activity; By the time the chyme is ready to leave the stomach, digests 30-40% of carbohydrate, 10-20% of protein and less than 10% of fat; empties in 1-4 hours Small intestine: 10’ long; most digestion occurs here; food stays 3-10 hours; villi (trap food stuffs)  each villus contains blood vessels and a lymph vessel; villi 10x; microvilli 20x; SI surface area is 600x tube Absorption Large Intestine: 3.5 ft.; 18-24 hours bacterial action (digest small amounts of fiver and forms Vit K and B12); absorption of water, sodium, chloride, potassium, some Vit K; lactose intolerance; formation of feces for elimination  ileocecal valve separates small intestine from large intestine Rectum: stool remains; stimulates elimination; muscle contraction; anal sphincters Influences on Digestion and Absorption  Psychological: taste, smell, presentation, expectations that food tastes good, environment  Chemical: preparation, digestibility, temperature  Bacterial: amount of stomach acid, microbes in large intestine GI disorders *Laxatives: draws water into the intestine; decrease muscle action; becomes dependent on it *Low FODMAP diet: FODMAPs are a collective group of carbohydrates commonly malabsorbed in the intestine, causing excess gas, bloating, and diarrhea. Hemorrhoids: Swollen veins of the rectum and anus; Intense pressure and straining; S/S: pain, itching, bleeding; eat plenty of fiber and fluid Diverticulosis: Small pouches develop along the large intestine; May become infected; May be chronic condition (worsened by low-fiber diets) Alternate Feeding Methods 1. Enteral or Tube feedings: who are unable to swallow, unconscious, or have suffered an injury to the upper GI tract; may be used in conjunction with eating 2. If the GI tract is not functional, nutrients can be provided directly into the bloodstream as total parenteral nutrition (TPN) Mouth o Ptyalin: this enzyme breaks down carbohydrates in to simple single molecule sugars o Amylase: his enzyme too, breaks down carbohydrates in to simple single molecule sugars o Bromelaine: is an anti-inflammatory compound, and tenderizes meat Stomach o Pepsin: breaks down proteins in to smaller peptides o Gastric amylase: breaks down carbs in to simple sugar o Gastric lipase: breaks down fat o Gelatinase: breaks down gelatin and collagen present in meat Pancreas o Trypsin: breaks down peptides in to amino acids o Chymotrypsin: breaks down proteins in to aromatic amino acids o Pancreatic amylase: converts carbs in to simple sugar o Elastase: breaks down elastin o Nuclease: converts nucleic acids in to nucleotides Intestine o Sucrase: breaks down sucrose to monosaccharides o Maltase: converts maltose to glucose o Lactase: converts lactose to glucose and galactose Chapter 4 Carbohydrates @ plant-based foods or dairy products Definition: organic compounds Structure: simple sugar (mono and disaccharides)  Simple carbohydrates: sugars  Complex: starches and fiber o Starches and sugars are digestible o Fiber is indigestible Monosaccharides C6 H12 O6 1. Glucose (Dextrose)  from photosynthesis (separate six H2O  H combines with CO2 to form glucose; O are released)  most abundant carbohydrate in nature (linked together and form starch)  Plays key role in foods and in body  Supplies NRG to cells, blood sugar, fuel for brain function  Glucose usually joined to other sugars to form disaccharides, starch or fiber 2. Fructose  Laevulose or fruit sugar; Sweetest of all sugars  Occurs naturally in fruits and veggies  Used as an additive in processed foods 3. Galactose  Part of lactose; rarely occurs as a monosaccharide in food Disaccharides (double sugar) 1. Sucrose = glucose + fructose  Table sugar (honey, maple syrup, fruits, sugar cane 2. Lactose = glucose + fructose  Milk sugar; human milk higher in lactose 3. Maltose = glucose + glucose  Seldom occurs naturally; forms when long chain of glucose (starch) break down Complex: Oligosaccharides   Short chains (3-10 sugar molecules) Example: Raffinose and Stachuyose @ dried beans, peas and lentils Complex: Polysaccharides (long chains of glucose) 1. Starch o @ plants (grains, legumes, starchy veggies o 3000 or more monosaccharides o amylose: straight chain polymer o amylopectin: highly branched polymer 2. Glycogen o @ living animals; skeletal muscle and liver (body stores 200-500 gm at a time) o highly branched 3. Dietary Fiber o Provides structure to plants (whole grains, legumes, fruits) o Indigestible carbohydrates: humans can’t digest fiber o Total fiber = dietary fiber (naturally @ foods) + functional fiber (added to food for beneficial) CHO Digestion and Absorption 1. Begins in mouth (5% starch): amylase digests starch into shorter polysaccharides and maltose 2. Stomach (very little): high acid stops salivary amylase action; fiber provides feeling of fullness 3. Small intestine (most): pancreatic amylase – breaks starch into maltose Digestive Enzymes o Highly specific to specific carbohydrates o Inability to break down = undigested o Remain in large intestine o Bacteria partially ferment or break down yielding gas o Oligosaccharides (3- carbon units) in legumes cause gas o Lactose intolerance CHO Absorption o Absorbed into mucosal cells by active transport and facilitated diffusion o Once in villi, monosaccharides travel to the liver via the portal vein where galactose and fructose are converted to glucose o Liver stores and releases glucose as needed to maintain constant Blood Glucose levels o Absorbed CHO in diet becomes glucose for use in body: the preferred fuel o Glucose taken up by cells, broken down into CO2 and water and NRG is released Glucose  After you Eat—immediately use some glucose to maintain blood sugar o After a meal, when blood glucose levels rise, the hormone insulin is released and directs glucose into your cells. Excess glucose is stored as glycogen in liver and muscle or as fat when glycogen stores are full (glycogenesis). o When blood glucose levels drop too low (during fasting), the hormone glucagon is released which directs the release of glucose from glycogen in your liver. Glucagon also signals the liver to begin producing glucose from non-carbohydrate sources such as protein. o Insulin and glucagon regulate blood sugar closely  Both hormones produced by Pancreas  During Fasting—Body Breaks down Fat and Protein: after about 18 hours of fasting, your liver’s glycogen stores are depleted, so your body must rely solely on fat and protein for fuel (gluconeogenesis) o To burn fat thoroughly, adequate amounts of glucose are needed. Without it, ketone bodies form (by-products of incomplete breakdown of fat) and these build up in the blood (ketosis) o Brain cells and developing RBC’s require constant supply of glucose o Body makes glucose from protein – your body begins to break down protein rich tissues to generate glucose, thus dietary carbohydrates spares body protein Regulation of Blood Glucose  Pancreas: insulin (the key that unlocks cells to allow blood sugar to enter; stimnulates liver and muscle to store glucose as glycogen  Pancreas: glucagon (stimulates breakdown of glycogen into glucose for use by cells; stimulates synthesis of glucose from protein)  Adrenal glands: epinephrine (“fight or fight” response: to ensure all body cells have adequate NRG for emergencies) Diabetes Mellitus  Body does not regulate BS adequately; Either too little insulin or resistant to effects  Hyperglycemia (elevated BS)  Cells have no access to blood glucose o “Starvation in the midst of plenty” o Triggers liver to make glucose from protein and use fat as an energy source, creating acidity (ketones)   o Kidneys unable to reabsorb glucose, excreted in urine Types: o Type 1: “Juvenile”  5 to 10 percent of cases  Autoimmune disease: insulin-producing cells in pancreas destroyed—insulin injections required  Develops in childhood, early adult years  Usually occurs in people <30 years of age  Sx: Excessive thirst, frequent urination, nausea, rapid weight loss  Require external source of insulin o Type 2: “Adult Onset”  90 to 95 percent of cases  Cells are resistant to insulin, eventually insulin-producing cells are exhausted, pancreas decreases and medication and/or insulin is required  People 45 and older or at risk for diabetes should be tested  Obesity plays a role  Diet and exercise, oral medications, insulin injections  Glycemic Index and Carbohydrate counting o Prediabetes: impaired glucose tolerance  Blood glucose higher than normal but not yet high enough to be classified as diabetes  Damage to heart and circulatory system can occur. Risk Factor o Family History o More frequently occurs in Native Americans, Hispanic Americans, African Americans o Type 2: obesity, especially around mid-section o No regular exercise o Women who had gestational DM o Metabolic Syndrome: hyperinsulinemia, dyslipidemia, hypertension, glucose intolerance o High sugar diet does not cause DM! o Prevention: Healthful diet, normal weight, regular exercise  Diet modifications o Regulate timing of meals; consistent carbohydrate intake; increase dietary fiber intake; consume low glycemic index foods; mixture of carbohydrate/protein and fat at snacks and meals Glycosylated Hemoglobin (HgA1c)  A blood test that reflects blood glucose concentration over the past 120 day  Works because ~ 120 days is the life span of a RBC and glucose is attached to hemoglobin in the blood stream    The best overall indicator of diabetes control A HgA1c level of 6% reflects an average glucose level of 120mg/dL over the past 3 months For every 1% decrease in HgA1c levels, complication rates decrease by 35-40% Gestational Diabetes  Affects 7% of pregnancies  90% of women who develop GDM resume normal glycemic control post pregnancy  Remain at risk for GDM in subsequent pregnancies  At risk for developing Type 2 DM  30-40% of obese women who develop GDM will develop Type 2 DM  Risk to babies:  Excess glucose delivered to the fetus; Higher fetal insulin levels; Increased fat deposition; High birth weight; Traumatic delivery; Low blood glucose & respiratory risk at birth; Risk for obesity at Type 2 DM later How much and what kind of CHO  AMDR  Minimum of 130 gm CHO required/d to prevent ketosis from incomplete fat metabolism and to provide glucose for your brain and red blood cells  Reduce intake of added sugars What’s the difference between natural and added sugars?  Natural: @ fruits and dairy (more nutrient dense; provide more nutrition per bite)  Added: added by manufacturers and are often empty calories (provide little nutrition) o 1 teaspoon = 4 grams of sugar High-Fructose Corn Syrup  Potential harmful health effects o Human studies on fructose: increased total energy intake, body weight, visceral adiposity, insulin resistance, dyslipidemia, gout o Animal studies of HFCS: increased body wt., metabolic syndrome  Caloric sweeteners have similar effects on body  Sucrose, HFCS, honey molasses, crystalline fructose, fruit juice concentrates: most contain fructose and provide 4 kcal per gram  Few human studies have compared different sweeteners  Sugar-sweetened beverages/added sugars lead to obesity  Harmful health effects of fructose relate to high intakes (not fructose in fruits and vegetables) Health • High sugar intake: Low nutrient content; Contributes to tooth decay; excess kcal, contributes to obesity • High fiber intake: Better control of blood glucose; Possible reduced cancer risk; Reduced risk of heart disease; Healthier gastrointestinal functioning How much CHO do you need?  Filling Up on Fiber  DRI: 14 grams of fiber per 1,000 calories to promote heart health  Most Americans fall short: about 15 grams per day  Gradually increasing fiber in your diet will minimize side effects, such as flatulence  As you add fiber to your diet, you should also drink more fluids   Adult Males: 38 g/day (AI) Adult Females: 25 g/day (AI) 2 types fiber Health Benefits of Dietary Fiber  Absorbs and holds water  Soften stool  Larger stool promotes peristalsis  Promotes regularity  Lower risk for cardiovascular disease  Decrease hemorrhoids and diverticula Sugar Practice Question Each morning for breakfast, Joe has: - 2¼ cups of Honey Nut Cheerios (9g sugar per ¾ cup serving) in 1 cup 1% milk with sliced banana - 16 oz black coffee with 2 teaspoons of sugar How many teaspoons of added sugar is he consuming at breakfast? 3 servings cereal × 9g/serving = 27g ÷ 4g/tsp = 6.75 tsp 6.75 tsp + 2 tsp = 8.75 tsp How many calories from sugar is he consuming? 8.75 tsp × 4g/tsp = 35g × 4kcal/g = 140 kcal How does his breakfast sugar intake compare to American Heart Association recommendations? His entire breakfast is all the added sugar he can eat for the day How does his breakfast sugar intake compare to the 2015 Dietary Guidelines for Americans recommendations assuming he should have a total of 2000 calories per day? 140 calories/2000 calories = 0.07 x 100% = 7% of total calories from added sugar He could have no more than 3% more added sugar in his diet for the rest of the day. Chapter 5 Lipids Lipids: compounds containing C, H, O, that are hydrophobic (insoluble in water) • Cushions and protects bones, organs and nerves • Insulates to maintain body temperature • Carry fat-soluble vitamins & nutrients • Supports developmental and physiological processes in various systems (immune, neurological, skin/hair, etc.) • Major building block of membranes • Create hormones Fat: one type of lipid (triglyceride) • A broad range of organic (containing carbon) molecules that dissolve poorly in water • Hydrophobic = water fearing • Lipophilic = fat loving • Three types of lipids found in foods and in your body: 1. Triglycerides (fats) 2. Phospholipids • Basic unit of triglycerides and phospholipids = fatty acids 3. Sterols  Naturally occurring fatty acids vary in chain length and degree of saturation Fatty Acids  @ triglycerides and phospholipids  Chain of carbon and hydrogen atoms with acid group (COOH at one end) o Over 20 different fatty acids o Can vary by:  length of chain  Varies from 4 to 24 carbon atoms o Short Chain (<6 carbons) o Medium-chain (6-10 carbons) o Long-chain (>12 carbons)  As chain length increases, fatty acids become more solid at room temperature (saturation also affects)  whether carbons have double or single bonds between them  Saturated fatty acids: all carbons bonded to hydrogen o Example: stearic acid, 18 carbons, solid at room temperature o Mostly straight due to single bondsàpack tightly together  Unsaturated fatty acids: one or more double bond between carbons (less saturated with hydrogen) o More liquid at room temperature  Monounsaturated fatty acids: one double bond o Example: Oleic acid, 18 carbons (olive oil) o Kinked fatty acid  Polyunsaturated fatty acids: more than one double bond o Example: essential fatty acids linoleic and alpha-linolenic acids (soybean oil)  total number of double bonds