Bio 1155 Test 1 notes.pdf

Ch1- nutrition research focuses on supporting health and preventing/treating chronic disease Organic nutrient: carbs, fat (lipids), protein (made of amino acid chains), vitamins Inorganic: minerals and water Micro nutrient: vitamins and minerals- needed in smaller quantities Energy yielding nutrient...

Ch1- nutrition research focuses on supporting health and preventing/treating chronic disease Organic nutrient: carbs, fat (lipids), protein (made of amino acid chains), vitamins Inorganic: minerals and water Micro nutrient: vitamins and minerals- needed in smaller quantities Energy yielding nutrients are fuel and are stored in the body Water helps with waste/nutrient transport, muscle contraction, nerve impulse, body temp and is a macronutrient There’s 13 vitamins, they support in energy production and regulatory processes but are vulnerable to destruction Vitamins can be fat soluble (A,D,E,K- toxicity can occur) or water soluble (C, B- excess secreted in urine) Minerals are inorganic, don’t produce energy, and are indestructible -important for fluid retention, energy production, bone/blood health -trace minerals >100 mg/day (>5g in body) major minerals >100 mg/day (>5g in body) -minor minerals- iron, zinc, copper, manganese, fluoride, -major minerals- calcium, phosphorus, sodium, potassium, chloride, magnesium, sulfur Nutrients assist in reactions to help maintain homeostasis B vitamins regulate the use of macros for energy Sodium help regulate blood volume (DRI) Dietary Reference Intake= identify the amounts of each nutrient that one needs to consume to maintain good health (EAR) Estimated Average Requirements=daily intake estimated to meet 50% of peoples needs (RDA) Recommended Dietary Allowances= daily intake estimated to meet most (~97%) peoples needs *ideal amounts* (AI) Adequate Intake= the level assumed to be adequate, use when EAR unavailable (UL) Tolerable Upper Intake Levels= highest levels without health risk. Do not exceed. (AMDR) acceptable macro distribution range= recommended range of carbs, fat, protein associated with reduced risk of chronic disease -45-65% kcal/daily from carbs -20-35% kcal/daily from fat -10-35% kcal/daily from protein (EER) Estimated energy requirements= the avg daily energy intake predicted to meet healthy adult needs and maintain energy balance (CDRR) Chronic disease risk reduction intake= methodology that focuses on reduction of disease risk (sodium is the only nutrient under CDRR) -nutrient that reduces risk with increased intake = reduction in disease risk -nutrients that increase risk with increased intake =increased disease risk Ch2- a healthful diet consists of a combination of energy and nutrients -adequate, moderate, nutrient dense, balanced, varied Sensory data- sight, smell, taste, texture, sound (stimulates gastric secretions and stomach motility) Social/cultural cues- occasions, location, activity, time of day, emotions Learned factors- family, community, religion, culture, new learnings/influence by friends, education, culture Food choices are based on preference (taste), habit, tradition/culture, social interactions, cost, convenience, associations, emotion, weight/image, benefits Half plate of fruit/veg. Aim for reduced saturated fat, sugar, salt Food labels should include: NFT, ingredients, allergens/gluten course, date, origin claims, composition claims, nutrition claims, production claims, common name Low fat means less than 3g/serving- rounding rules are followed. 3.4=3g 3.5=4g (no longer low fat) A healthy diet has 3 key principles: 1) everything you eat counts 2) primarily nutrient dense food 3) adaptable eating patterns to be healthy in any sociocultural enviro Ch3- two prompts to seek foodappetite: stimulated by sight, smell, thought of food hunger: physiological drive to eat Ghrelin- increases in hunger (stimulates appetite) decreases after eating CCK (cholecystokinin)- decreases hunger, increases after eating. CCK is in the small intestine. Leptin- increases satiety, increases after eating. Leptin is in fat cells. The hypothalamus regulates hunger and contains nerve cells called the feeding centre, which triggers hunger, and the satiety centre that inhibits feeding entre cells to prompt no more eating The pressure response is a nervous response. Stretch receptors signal the hypothalamus that we are full. This is why we should wait before eating more- allows brain to process fullness Nerve cells (pressure/nutrients) -> hypothalamus -> suppress satiety centre, leading to feeding Hormones (ghrelin, CCK, leptin) (chemical signals) -> hypothalamus -> increase/decrease satiety Protein, bulky high in fibre food, water and solid foods (vs semi solid ex. smoothie/soup) provide best satiety Digestion: mouth (mixes food with saliva= bolus), salivary glands, pharynx (swallows bolus), esophagus (moves food to stomach), stomach (mixes food, releases hydrochloric acid and protein digestive enzyme), liver (makes bile to help digestion/absorption), pancreas (releases bicarbonate, produces digestive enzymes), gallbladder (stores bile and emulsifies fat, releases to SI), SI (absorbs nutrients into blood/lymph), LI (absorbs water/vitamins/minerals, has intestinal bacteria, anus (allows waste to leave body) Protease- breaks down proteins Amylase- breaks down carbs Lipase- breaks down fat HCO3 (bicarbonate) from pancreas neutralizes gastric juices Food entering the SI stimulate hormonal and nervous system signals Lysozomes: reduce bacteria in mouth. Fewer lysozomes= bad breath Enzymes assist in nutrient movement, they are transportation and remain unchanged. Not enough enzymes=indigestion. Enough enzymes= efficient transportation/absorption Epiglottis is the flap that separates trachea (connects to lungs) and esophagus (connects to stomach) Enzyme > two separate compounds enter enzyme > compounds join together > new compound formed, leaves enzyme as one > enzyme Parietal cells: in the stomach lining that make hydrochloric acid and intrinsic factor in response to nervous/hormonal stimulation Gastrin Hormone: secreted by G cells to stimulate gastric juices HCI (hydrochloric acid): denatures protein breaking it into amino acid chains, activates pepsin IF (intrinsic factor): critical in the absorption of vitamin B, produced by the parietal cells Pepsinogen: inactive protein digesting enzyme produced by gastric glands. Activated by HCI to become pepsin. Indirectly acts on protein- needs to become pepsin first) Pepsin: protein digesting enzyme produced by gastric glands, activated by HCI in the stomach. Directly acts on protein. Chief cells: secrete pepsinogen Epithelial cells= parietal cells, gastric cells, chief cells chief cells > pepsinogen> pepsinogen + HCI = pepsin = protein breakdown small intestine is made up of the duodenum, jejunum, ileum (most digestion/absorption happens in the SI through pancreatic en zymes and bile) gastroesophageal sphincter is top of the esophagus, esophageal (cardiac) sphincter is bottom of the esophagus, the pyloric sphincter separates the stomach and SI, ileocecal sphincter is the end of SI allowing emptying to LI chemical digestion continues in the SI using pancreatic enzymes and bile the gallbladder contracts in response to CCK secretion, bile emulsifies fat pancreas manufactures and secretes enzymes and bicarbonate CCK is a hormone released from the duodenum to stimulate the release of pancreatic juice, causes the gallbladder to release bile Lacteals in the SI absorb fat soluble nutrients Simple diffusion, osmosis, and facilitated diffusion don’t require energy (solute movement from high concentration to low concentration) Active transport requires energy because its moving against the gradient going from low concentration to high concentration The hepatic portal vein transports water soluble nutrients (CHO, protein, minerals, C and B vitamins) from the SI to the liver Liver stores fat soluable vitamins (A,D,E,K) and B vitamin to make blood protein Fat soluble nutrients and some vitamins enter the lymphatic vessels through the blood stream through lacteals in the SI, collecting in the thoracic duct via the left subclavian vein Water, and some vitamins and minerals absorbed in the large intestine (Very little digestion occurs in LI) GI flora (gastrointestinal bacteria) help digest complex CHO/protein, synthesize vitamins, inhibit growth of harmful bacteria, stimulate the immune system Endocrine (hormonal) system and nervous system coordinate during digestion The colon and rectum store food waster until excreted through the coccal value to LI- may remain 12-24 hours before elimination Neuromuscular system regulates activity in the GI tract- voluntary and involuntary muscle (chewing/peristalsis/churning of stomach) Nerves control the contractions and secretions of the GI tract (enteric nervous system, some branches of the autonomic nervous system, central nervous system) Gastrin responses to food in stomach, secreted fom stomavch wall stimulating the stomach glands to release hydrochloric acid Secretin responds to chyme in SI, sectreted from duodenal wall, stimulated the pancreas to release bicarbonate into SI CCK responds to fat/protein in small intestine from the intestinal wall, stimulates the pancreas and gallbladder to release bile and bicarbonate to SI Ulcers are lesions in the GI tract eroded by HCI and pepsin Food intolerance has unpleasant symptoms and is not an allergy. An allergy causes an inflammatory autoimmune response.