Nutrition Final Exam Study Guide PDF

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Professor Melissa Greives...

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Nutrition Final Exam Study Guide Macronutrients-energy-yielding  Carbohydrates o provide glucose to cell for primary source of energy o Part of genetic material (DNA, RNA) o Maintain health of GI tract (dietary fiber)  Proteins o Source of energy o Major structural material in body (muscle, skin, bone [collagen]) o Allows communication systems to work (protein hormones) o Maintains immune system (antibodies) o Enzymes=chemical reactions needed for life  Lipids o Provide large amounts of energy o Provide structure of cell membranes o Regulate cellular processes (eicosanoids) o Assist with development and structure of brain, nervous system and reproductive system  Carbohydrates – 4kcal/gram  Protein- 4kcal/gram  Lipid- 9kcal/gram  Alcohol- 7kcal/gram  AMDR o Carbohydrates – 45-65% total daily kcals o Protein- 10-35% total daily kcals o Lipids- 20-35% total daily kcals Micronutrients  Minerals, vitamins, water EAR-Estimated Average Requirements o Average amount sufficient for 50% of the population RDA-Recommended Dietary Allowances o Recommendations to meet needs of practically all (98%) healthy people AI-Adequate Intakes o Insufficient scientific evidence to establish RDA-rather rely on scientific judgement vs. RDA has scientific evidence o Expected to exceed average requirements UL- Tolerable Upper Intake Levels  Point where nutrient is likely to be toxic  Helps protect against overconsumption

Epidemiological Studies- investigate the incidence, distribution and control of disease in a population and can include cross-sectional, case-control and cohort studies  No intervention is implemented  Used when there is insufficient knowledge to make a cause and effect hypothesis or when conducting another type of study would be impractical or unethical o Advantage: Can explore complex interactions that exist among genetic, environmental and lifestyle factors o Disadvantage: cannot control variable, cannot prove a causal relationship, and may not be representative of an entire population Experimental Studies- testing for causal relationships, an experiment in which something is altered or changed to determine its effect on something else  Advantages: can control conditions, determine cause and effect, can apply some findings on humans to some groups of humans  Disadvantages: cannot apply results from animals or test tubes to humans  Cannot generalize findings on humans to all humans  Cannot use certain treatments for clinical or ethical reasons Dietary Guidelines for Americans  Evidence-based food and beverage recommendations for Americans ages 2 and older o Promotes health, prevent chronic disease, help people reach and maintain a healthy weight  Variety, nutrient density and amount o Naturally lean or low in solid fats and have little or no added solid fats, sugars and refined starches or sodium  Limit calories from added sugars and saturated fats  Variety of vegetables  Fruits  Grains (at least half whole grain)  Fat-free or low-fat dairy – milk, yogurt, cheese, fortified soy beverages  Proteins foods – seafood, lean meats and poultry, eggs, legumes and nuts, seeds, and soy products

Digestive tract- mouth, esophagus, stomach, small intestine, large intestine, rectum, anus Pyloric sphincter  Opens into small intestine Mucus  Protects stomach wall cells from acid  Cells of entire GI lining secrete mucus to protect self from acid, enzymes, and disease-causing bacteria Gallbladder  Bile emulsifies fat so that enzymes can have access to break it down Bile  Emulsifier bringing fats into suspension with water allowing enzymes to access fats  Produced by the liver, stored in gallbladder, released into duodenum Colon  Intestinal bacteria ferment some fibers o Producing water, gas, and fragments of fat that provide energy for the colon cells  Absorbs recyclable materials o Water and dissolved salts Villi  Composed of hundreds of cells covered in microvilli (tiny hairs)  Select and regulate nutrients absorbed based upon needs  Different parts of the GI tract absorb different nutrients- those that are easier to digest are absorbed earlier on than those that take longer to digest Pancreatic juice  Break down carbohydrates, fats and proteins pH of chyme in stomach = 2 – very acidic pH of chyme in GI tract = 6 almost neutral Microbes in GI Tract  100 trillion microbes, not harmful Lymphatic System  the first major organ to receive nutrients from the lymph go to the heart first which pumps them to all the body’s cells  the body’s cells remove the nutrients they need and the liver deals with the remnants

Monosaccharides

Glucose – blood sugar o Simple sugars o Essential energy source o Part of every disaccharide  Fructose o Sweetest of all sugars o Naturally occurs in fruit and honey o High fructose corn syrup  Galactose o Rare o Occurs naturally in foods Disaccharides  Maltose – glucose and glucose  Sucrose – glucose and fructose  Lactose – galactose and glucose 

Glycogen  Storage form of energy in the body  Stored in the liver – adipose tissue Liver  Fructose and galactose mostly metabolized here  Fructose and galactose are converted to glucose here  Glucose is pumped from liver into general circulation Saturated Fatty Acids  full of hydrogens Unsaturated Fatty Acids  missing hydrogens – has double bonds Lipoproteins  Chylomicrons o Largest and least dense o Little protein and mostly triglycerides  VLDL o Half lipids, some cholesterol, phospholipid and protein  LDL o VLDL becomes LDL o Highest % of cholesterol  HDL o Liver makes HDL to remove cholesterol from cells and carry back to liver for recycling or disposal o Lowers risk of heart disease by clearing cholesterol and has antiinflammatory properties o Less lipid and is half protein Eicosanoids

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Derived from linoleic and linolenic FA Derivatives of 20 C FA Biologically active compounds that have health effects

EPA  Fish and fish oil DHA  Fish and fish oil Lipoprotein lipase  Hydrolyzes triglycerides from circulating lipoproteins, releasing FA, diglycerides and monoglycerides into adipose cells Foods that contain cholesterol  Healthy o Eggs o Cheese o Shellfish o Organ meats  Unhealthy o Fried foods o Processed meats o Desserts Major source of HDL  Fatty fish  Exercise increases HDL

Nitrogen Balance  Zero nitrogen balance o Nitrogen intake = nitrogen output o Healthy adults, protein synthesis balances with degradation and protein intake from food balances with nitrogen excretion  Positive nitrogen balance o If body synthesizes more than it degrades, nitrogen intake exceeds nitrogen excretion o Growing infants, children, adolescents, pregnant women  Negative nitrogen balance o Body degrades more than it synthesizes (protein being lost) o Nitrogen excretion exceeds their nitrogen intake o Starvation, severe stress, or nitrogen losses

Deaminating amino acids

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Results in o Ammonia o Keto acid  Used for energy, production of glucose, ketones

Transamination  The transfer of an amino group from one AA to a keto acid producing a new nonessential AA and a new ketoacid Linoleic Acid  18 C  Omega 6  Vegetable oil, meats Linolenic Acid  18 C  Omega 3  Flax seed, walnuts, canola oil Fat cell development  Adipogenesis – accumulation of lipids and an increase in the number and size of fat cells Ghrelin  Hormone produced and released by the stomach  Stimulates appetite  Promotes fat storage Leptin  Hormone made by adipose cells that helps regulate energy balance and inhibits hunger Essential Amino Acids  Histidine  Isoleucine  Leucine  Lysine  Methionine  Phenylalanine  Threonine  Tryptophan  Valine o HILL Make People Think To Vomit Protein synthesis is limited  Body only makes whole proteins, if 1 AA is missing it cannot form a “parital protein” and protein synthesis will be halted  If you’re lacking an AA protein synthesis will be halted

Complementary proteins  Low-quality proteins (deficient of essential AA) combines to make adequate levels of essential AA  Not necessary to balance AA at each meal but rather during a whole day o Legumes, grains, nuts and seeds

Coenzyme  An organic molecule required for the functioning of enzymes; work with enzymes to facilitate the enzymes activity Glycolysis  Metabolic breakdown of glucose to pyruvate  Anaerobic Anaerobic – no O2 – quick energy needs Aerobic – requires O2 – slow energy needs Cori cycle  Lactate in muscles is transported to liver where it is converted back to glucose and go back to working muscles Carbohydrates can more easily be converted to glucose than fat or protein FA (Lipids) cannot be converted to glucose Body uses protein when diet is insufficient in carbs

BMI=weight*703/height^2 Healthy weight = 18.5-24.9 Overweight = 25-29.9 Obese = 30-39.9 Intra-abdominal fat  Fat within abdominal cavity/internal organs  Contributes to heart disease, cancers, diabetes  More common in males and women past menopause Factors that determine body’s metabolic rate  Age – lean body mass diminishes with age – slowing BMR  Height- tall, thin people have higher BMR  Growth – children and pregnant women is higher  Fever and stress raise BMR

3,500 kcals = 1 pound Lose 5-10% of body weight = 6 months or .5-2lbs/week Bioavailability  the rate and the extent to which a nutrient is absorbed and used by the body B-Vitamins  without B vitamins the body would lack energy  do not provide the body with fuel for energy, but they help the body use macros for fuel Pernicious anemia  B12 deficiency  Folate masks symptoms of B12 deficiency Folate  Leafy green vegetables, legumes, seeds, liver, fortified grains B12 

Animal products o Meat, fish, poultry, shellfish, milk, cheese, eggs, fortified cereals o Bioavailability highest in meat and dairy

Fat soluble vitamins  Require bile for digestion and absorption  Excesses stored in liver and adipose tissue  Not readily excreted Beta Carotene  The carotenoid (pigments derived from plants; some can be converted to VitA) with the greatest Vitamin A activity  Precursor (can be converted to vitamin A in the body) to Vitamin A Vitamin D  Cholesterol is the main precursor for body’s synthesis (need sunlight) o Plant foods and Animal sources o Synthesis via skin and sunlight Vitamin A  Vision and growth Vitamin D deficiency  Rickets – bones fail to calcify normally in children and cause bones to bend  Osteomalacia – poor mineralization of bones – softening of bones – adults

Vitamin E  Antioxidant  Primary defender against the adverse effects of free radicals Vitamin D  Bone growth Vitamin K  Blood clotting  Metabolism of bone proteins

Main organ responsible for homeostasis of body fluids  Kidneys provide major control for homeostasis of body fluids and are central to regulation of blood volume and BP Antidiuretic Hormone  Water-conserving hormone produced by the pituitary gland in response to dehydration o Stimulates kidneys to reabsorb more water (excrete less) Potassium deficiency  Low intake of fruits and vegetables  Increase in blood pressure  Salt sensitivity  Kidney stones  Irregular heartbeats  Muscle weakness Phosphorus  Second most abundant mineral in the body  Major buffer system  Part of DNA and RNA  Energy metabolism  Transport lipids in blood  Structural component of cell membranes Kidneys and lungs help to maintain blood pH of 7.4 Iron 

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Heme iron o Animals foods o High bioavailability Nonheme iron o Plant and animal foods

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o 17% absorbed Iron enhancers o Meat, fish, poultry promotes absorption of nonheme iron foods Iron overload o Caused by free radical damage o Toxic accumulation in liver, hearts, joints

Selenium  Antioxidant Carbohydrates  main fuel source for endurance sports Fat  main fuel source for light-intensity to moderate-intensity exercise Creatine Phosphate System  extreme intensity lasting 5-10 seconds – anaerobic o 100m sprint Lactic Acid System  Very high intensity lasing 20 seconds to 1-3 minutes o ATP from anaerobic glycolysis (Cori Cycle) Aerobic System  High intensity lasting 2 to 20 minutes o ATP from carbohydrates oxidation (glycolysis and TCA cycle) o Cycling, swimming, running Creatine supplementation  Nitrogen containing compound that combines with phosphate to form high energy compound creatine phosphate in muscles o More creatine in muscles, higher intensity at level of training  Weightlifting or sprints Caffeine for athletes  Enhances endurance, alertness and reduces fatigue Caffeine during pregnancy  High intakes >3cups coffee/day – risk of miscarriage  Low intakes...