NATS1560 Test 1 Review PDF

Lecture 1 Science & Technology Science Systematic study to gain knowledge about the natural world. Technology Practical application of scientific knowledge. BOTH SOCIAL PROCESSES Technoscience A blend of science and technology. Social process, often controversial due...

Lecture 1 Science & Technology Science Systematic study to gain knowledge about the natural world. Technology Practical application of scientific knowledge. BOTH SOCIAL PROCESSES Technoscience A blend of science and technology. Social process, often controversial due to its societal, political, and ethical implications. Modern Science Characteristics Materialism Everything is physical, governed by laws of matter and energy. Reductionism Complex systems reduced to their smallest components (atoms, molecules). Experimentalism Knowledge must be supported by experiments. Food & Nutrition Nutrition Science Study of how food nourishes the body. Both nutrition science and food science are reductionist. Food Science & Technology Research on food properties for creating new products, methods, and preservation. Foods Substances we eat Complex mixtures containing nutrients. Food is deeply tied to culture. Nutrients Chemical components in food that provide nourishment. Chemical components identified to support health. Nutritional Needs Macronutrients Carbohydrates - Sugars (simple) and starches (complex) Fats - Saturated and unsaturated. Proteins - Made of amino acids. Micronutrients Minerals ○ Major - Calcium, magnesium ○ Electrolytes - Sodium, potassium ○ Trace - Iron, Zinc Vitamins ○ Water-soluble - B (complex) and C ○ Fat-soluble - A, D, E, K Phytochemicals ○ Still under study ○ Includes carotenoids and polyphenols. Categories of Food we Eat Meats, Poultry, Fish & Seafood: Primary protein source from skeletal muscles. Beef: Commonly from steers or heifers; industrial farming uses corn, reducing nutritional value. Pork: From domesticated pigs, high fat content, requires thorough cooking. Poultry: Chicken, turkey, eggs; industrially raised. Fish & Seafood: Omega-3 fatty acids (polyunsaturated - liquid at low temp); aquaculture and overfishing issues. Grains Most common: Grass Kernel - Pollinated ovary of grass. ○ Endosperm - Inner portion (starch and protein) ○ Embryo (Germ) - Base (enzymes and oil) Gluten - Like rubber bands when mixed with water; chewiness and rising of bread and pastries. Big 3: Wheat: Richest in protein.  ○ Emmer ○ Durum ○ Bread ○ Kamut ○ Spelt ○ Farro ○ Bulgher Rice: Most popular staple ○ Basmati ○ Short-grain ○ Sticky rice ○ Instant ○ Converted Corn (Maize): Used for animal feed and human consumption. ○ Flour ○ Dent ○ Sweet Other Grains - (Oats, Barley, Millet, Rye, Quinoa (technically not grains but treated as such). Pulses (Beans and Lentils) High in protein, but often lack complete amino acids (e.g., beans, lentils). Common varieties include soybeans, chickpeas, and lima beans. Tubers & Root Vegetables Potatoes: Most popular, high in starch. Sweet Potatoes & Yams: Not related, high in beta-carotene. Cassava: Tropical root, must be processed to remove cyanide. Vegetable Families Nightshades: Potatoes, tomatoes, peppers, and eggplants. Brassicas: Broccoli, kale, cabbage, cauliflower. Alliums: Onions, garlic, leeks. Fruits Temperate Fruits: Apples, pears, berries (strawberries, blueberries). Warm Climate Fruits: Tropical fruits (mango, pineapple, banana), citrus (oranges, lemons). Nuts, Seeds, and Oils Nuts: High in protein and fat (e.g., almonds, walnuts, peanuts).  Oils: Mostly from seeds (e.g., canola, sunflower, olive oil). Lecture 2 Carbohydrates Definition Organic compounds made of carbon, hydrogen, and oxygen; main source of energy for the body. Types Monosaccharides (single sugars): glucose, fructose, galactose. Disaccharides (double sugars): sucrose, maltose, lactose. Oligosaccharides: short chains of monosaccharides (e.g., in human milk). Polysaccharides: long chains (e.g., starch, glycogen, cellulose). Digestibility Digestible: Starch (plants' energy store), glycogen (animals' energy store). Indigestible: Dietary fiber (e.g., cellulose, inulin), adds bulk and aids digestion. Carbohydrate digestion: Simple sugars are quickly digested, while fibers slow absorption and aid digestion. ○ Breaks down starches in mouth with salivary amylase. ○ Continues to the small intestine - pancreatic amylase. ○ Absorbed as monosaccharides in the bloodstream. Functions Provide energy: 4 kcal/g. Dietary fiber slows sugar absorption and aids digestion. Food Sources Sugars: Milk, honey, fruits, vegetables. Starches: Grains, tubers, bread, pasta. Fiber: Whole grains, vegetables, pulses, fruits. Fats Definition Organic compounds mainly composed of triglycerides, providing energy and supporting cell structure. Types of Lipids Triglycerides: Fats and oils in food, main storage form of fat. ○ 3 fatty acids + glycerol Phospholipids: Cell membrane components; help fat transport in the blood. Steroids: Cholesterol, steroid hormones, bile acids, Vitamin D. Fatty Acids Saturated (SFA): Single carbon bonds (e.g., butter, meat fats). Unsaturated (UFA): One or more double bonds. ○ Monounsaturated (MUFA): One double bond (e.g., olive oil). ○ Polyunsaturated (PUFA): Multiple double bonds (e.g., fish oils). ○ Essential fatty acids: Omega-3 (ALA), Omega-6 (LA) – necessary but not produced by the body. Functions Energy source: 9 kcal/g. Essential fatty acids for cell function. Body insulation, organ protection, transport of fat-soluble vitamins, hormone production, cell membrane integrity. Food Sources Saturated fats: Meat, dairy, coconut oil. Unsaturated fats: ○ MUFA: Olive oil, avocado, peanuts. ○ PUFA: Fish, nuts, seeds, vegetable oils. Trans Fats Artificial: Formed by hydrogenation (e.g., margarine), raise LDL (bad cholesterol) and lower HDL (good cholesterol). Banned in many countries. Natural: Small amounts in meat and dairy. Rancidity Lipolytic: Breakdown of fats by microbes (e.g., in cheese). Oxidative: Damage by oxygen causing free radicals (aging and diseases). Fat metabolism Triglycerides are broken down into fatty acids for energy. Essential fatty acids must come from the diet. Health Impact of Fats Balance of different fatty acids (saturated vs. unsaturated) is critical for heart health. Lecture 3 Proteins Structure Proteins: Polymers of amino acids. Amino Acids: Amine group, carboxyl group, and side chain. Polypeptide: Chain of amino acids; folded into proteins. Amino Acid Types Essential: Must be from food (e.g., lysine, leucine). Conditionally Essential: Needed from food under certain conditions (e.g., arginine). Non-essential: Made by body (e.g., alanine). Protein Functions Structure (e.g., keratin, collagen). Enzymes (e.g., lactase - digestive). Hormones (e.g., insulin, growth). Muscle contraction (e.g., actin, myosin). Immune response (antibodies). Transport (e.g., hemoglobin). Energy (can be used in absence of carbs and fats). Sources Complete: Meat, fish, eggs. Incomplete: Beans, grains. Micronutrients Definition: Needed in small amounts, no energy provided. Types: ○ Vitamins: Organic (from plants/animals). ○ Minerals: Inorganic (from soil/plants). Vitamins 1. Fat-Soluble:  ○ A: Vision, immune system. Sources: liver, carrots. ○ D: Calcium absorption. Sources: sun, fish. ○ E: Antioxidant. Sources: nuts, seeds. ○ K: Blood clotting. Sources: leafy greens. 2. Water-Soluble: ○ B-Vitamins: Coenzymes. B1 (thiamine): Prevents beriberi. B3 (niacin): Prevents pellagra. B12: Animal products. ○ C: Antioxidant, immune function. Sources: citrus. Minerals 1. Major: ○ Calcium & Phosphorus: Bones/teeth. ○ Sodium & Potassium: Fluid balance, nerves. ○ Magnesium & Chloride: Metabolism. 2. Trace: ○ Iron: Hemoglobin ○ Zinc: Skin, immune system ○ Iodine: Thyroid ○ Fluoride: Teeth health. Water Functions: Solvent, regulates temperature, waste elimination, cushions joints. pH: Measures acidity/basicity ○ Basic = 9 (egg white), Neutral = 7 (water), Acidic = 1 (stomach acid) Deficiencies Vitamin A: Blindness, immune issues. Vitamin D: Rickets B1 (thiamin): Beriberi B3 (niacin): Pellagra Vitamin C: Scurvy Iron: Anemia Lecture 4 Energy Food and Energy Why We Need Food: For matter (growth/repair) and energy (physiological processes). Energy Forms: Kinetic (motion), thermal (heat), chemical (stored in bonds). Cellular Respiration: Oxidation of food molecules to produce ATP (energy carrier), heat, CO₂, and H₂O. ○ Glycolysis: Glucose → pyruvate (2 ATP) ○ Krebs Cycle: Pyruvate → CO2 (2 ATP) ○ Electron Transport Chain: Makes ~32 ATP using oxygen. Measuring Food Energy Calories (kcal): 1 kcal = energy to raise 1 kg of water by 1°C. Energy Requirements: Vary by height, weight, age, activity level, etc. Macronutrients Macronutrient Energy Values (Atwater Values): ○ Carbohydrates: 4 kcal/g ○ Fats: 9 kcal/g ○ Proteins: 4 kcal/g ○ Alcohol: 7 kcal/g 4-9-4 Rule: Estimate energy from food: 4 kcal/g (carbs/proteins), 9 kcal/g (fats). Energy Use in the Body Basal Metabolism: Energy needed to stay alive (2/3 of total energy). Highest in infancy, declines after 50. Thermic Effect of Food: ~10% of energy from food is used in digestion. Food in the Body Digestive System Mouth: Chews food; saliva (amylase) breaks down starch. Esophagus: Moves food via peristalsis. Stomach: Secretes hydrochloric acid and pepsin; turns food into chyme. Small Intestine: Enzymes from pancreas digest nutrients, absorbed through villi. Large Intestine: Absorbs water, houses bacteria to complete digestion, forms waste. Enzymes and Hormones Enzymes: Biological catalysts; lower activation energy. Insulin: Lowers blood glucose by promoting nutrient uptake into cells. Glucagon: Raises blood glucose by signaling glycogen breakdown. Metabolism Definition: All chemical processes converting food into energy and body molecules. Metabolic Pathways: Sequences of reactions, controlled by enzymes. Diabetes Type 1: Insufficient insulin production. Type 2: Insulin resistance. The Liver (largest organ) Functions: Synthesizes glycogen, stores vitamins, produces bile, filters toxins, makes blood proteins, makes cholesterol and other lipids. Urinary System Kidneys: Filter waste/toxins, regulate water and ion balance. Bladder & Urethra: Store and excrete urine. Lecture 5 Food Safety & Foodborne Illnesses Food Safety: Practices ensuring food is free from harmful substances (toxins, contaminants). Foodborne Illness: Disease caused by harmful substances in food or drink. Endogenous Toxins Endogenous Toxins: Harmful substances naturally part of an organism. ○ Examples: Solanine: Potatoes, tomatoes. Oxalic Acid: Rhubarb, spinach. Amygdalin: Cassava, apricot kernels. Protease inhibitors: Raw beans. Mushroom toxins: Amanita verna. dotoxin: Puffer fish. Biological Contaminants Bacteria: ○ Examples: E. coli, Salmonella, Listeria, Campylobacter. Viruses: Norovirus, Hepatitis A. Parasites: Tapeworms, Giardia lamblia. Fungi: Mycotoxins (Aflatoxins, Ergot).  Prions: Cause diseases like BSE (Mad Cow Disease). Common Chemical Contaminants Unintentional: ○ Heavy metals: Mercury, lead, cadmium. ○ Fire retardants: PBDEs. ○ PCBs, furans, dioxins. Intentional: ○ Pesticides: Organochlorines (DDT), organophosphates. ○ Hormones: Synthetic estrogen, rBGH. ○ Antibiotics. Persistent Organic Pollutants (POPs) POPs: Toxic chemicals that persist in the environment, bioaccumulate, and biomagnify in food chains (e.g., DDT, PCBs). ○ Health Risks: Cancer, endocrine disruption, immune damage. ○ Bioaccumulation: Build-up of pollutants in an organism. ○ Bioamplification: Increased concentration up the food chain. Toxins from Cooking & Packaging Nitrites & Nitrates: Used in processed meats (risk: nitrosamines). PAHs: From smoking/charring food. Plastic chemicals: BPA, phthalates from plastic packaging. PFOA: Teflon cookware. Food Allergens Allergen: Triggers an abnormal immune response in sensitive individuals. ○ Common Allergens: Peanuts, shellfish, milk, eggs, gluten (celiac disease). Protection Against Foodborne Illnesses Key practices: Clean water, hygiene, proper cooking (70°C for pork/beef), prevent cross-contamination, proper food storage (cold 60°C). Review Questions 1. Which is NOT an intentional chemical contaminant? Mercury 2. Which is NOT an unintentional chemical contaminant? Antibiotics 3. Which contaminant comes from cookware? PFOA (Teflon) 4. Source of tetrodotoxin? Puffer fish 5. Source of solanine? Potatoes