Nutrition exam 2 review
Nutrition exam 2 review NTDT 20403
Popular in Nutrition
Popular in Nutrition and Food Sciences
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
This 12 page Study Guide was uploaded by Jazmine Morales on Wednesday February 17, 2016. The Study Guide belongs to NTDT 20403 at Texas Christian University taught by Dr. Powell in Spring 2016. Since its upload, it has received 45 views. For similar materials see Nutrition in Nutrition and Food Sciences at Texas Christian University.
Reviews for Nutrition exam 2 review
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/17/16
EXAM 2 Exam review- CHO and Lipids- Chapter 4 and 5 1. What are the food sources of CHOs? Sugar & Starch (grains) fruits, veggies, breads, pasta, potatoes All foods EXCEPT meat, fish, & pure fats (vegetable oils) 2. What are the monosaccharides, disaccharides, polysaccharides? Where are they found? Monosaccharides= glucose, fructose, galactose Glucose→ a.k.a. dextrose; not as sweet; measured in blood sugar or glucose Fructose→ sweetest sugar; fruit sugar; pentagon shape Galactose→ part of lactose (milk sugar) Disaccharides= maltose, sucrose, lactose Sucrose→ table sugar; occurs naturally via fruit Lactose→ 30-50% milk energy (dairy) Maltose→ malt sugar; germination of seeds, barley Polysaccharides (complex CHOs)= starch; storage form of glucose in plants plant polysaccharide glycogen; storage form of glucose in animals; made & stored in liver & muscle 3. Know the G words What they are? ◦ glucose, galactose, glycogen, glycerol & glucagon Where are they found? Glucose→ stimulates pancreas to release insulin 6 carbons Glycogen→ stored in liver & muscles; excess glucose into fat storage Pancreas release glucagon→ EX: starvation mode, more needed if athlete Glucagon stimulates liver cells Gluconeogenesis Making glucose from a non-CHO source; mainly in liver What is their function? ◦ Glucose→ person eats=blood glucose rises; person uses=blood glucose declines ◦ Glucagon→ is secreted when glucose levels are low by alpha cells; raises blood sugar levels ◦ Glycerol triglycerides= 3 fatty acids; backbone; contain mixture acids glucose out of its storage form in liver ◦ Glycemic effect Extent to which a food raises blood glucose concentration and elicits an insulin response **Foods that have potential for raising blood glucose, eliciting insulin response ◦ Glucagon breaks down glycogen & release glucose into blood ***Glucose= fuel required by brain, nerve cells & developing RBCs 4. Condensation and hydrolysis reactions- know what they are and when they occur Hydrolysis of a disaccharide: Maltose splits into 2 glucose molecules with H added to one & OH to the other(water) Condensation of a monosaccharide & disaccharide 2 glucose molecules create H2O 2 glucose molecules bond with a single O atom to form disaccharide maltose **After high CHO meal, liver cells cause excess glucose molecules to link by (condensation) **When blood glucose falls, liver breaks down glycogen→ glucose (hydrolysis) 5. Different types of fibers, roles of each, recommended amount Soluble fiber→ fruit, oats, barley, legumes Decreases cholesterol→ binds bile acids Decreases the rate of glucose absorption Used to treat diarrhea Insoluble fiber→ vegetables, wheat, grains Decrease transit time in SI Prevention of some cancers Must be used moderately by people with marginal intakes Helps in excretion of stools Phytic acid→ fibrous foods (husks of grains, legumes & seeds) binds minerals; Zn,Ca,Mg, Fe, Cu Cellulose→ composes plant cell walls; composed of glucose molecules Hemicelluloses→ main constituent of cereal fibers Pectin→ viscous; fruits & veggies; CHO backbone; thickens jelly & keep salad from separating Gums & mucilages→ plant secretes gums @ site of injury EX: Guar & carrageenan common mucilages (food stabilizers) Lignin→ nonpolysaccharide fiber; tough *** For dietary fiber; everything EXCEPT lignin’s & cellulose are digestible **** ACS recommends 20-35g daily fiber→ eating more fruits, veggies, legumes & less meat 6. Digestion and absorption location of CHOS **Ultimate goal is to render all available CHO into small compounds the body can use **Dextrins→ short chains of glucose units resulting from starch breakdown; thickens food STARCH: Mouth & salivary glands secrete saliva; amylase begins digestion Stomach acid inactivates salivary enzymes; halting starch digestion Pancreatic amylase is released into the SI SI= major site of nutrient absorption!!!!!!!! FIBER: Mechanical action of mouth crushes fiber Fiber is not digested in the stomach or SI; delays absorption in SI Bacterial enzymes digest fiber in large intestine Fiber holds water; regulates bowel activity; & binds substances (bile, cholesterol, minerals) 7. Enzymes involved in CHO digestion **Disaccharidase enzymes are hydrolyzed into monosaccharides (end-products of CHO digestion) Maltose→ maltase; glucose+glucose Sucrose→ sucrase; glucose+fructose Lactose→ lactase; glucose+galactose ***Monosaccharides enter capillaries of villi→ then travel to liver→ galactose & fructose share metabolic pathways with glucose→ glucose is used 8. Blood sugar regulation- hormones involved **Brain & nervous system use glucose as exclusive fuel source If glucose levels arehigh; beta cells in pancreas secrete insulin If glucose levels arelow; alpha cells in pancreas secrete glucagon Glucagon hormone that brings glucose out of it storage form in liver Insulin hormone that acts to take glucose out of the blood and deposit it into cells Epinephrine secreted by adrenal gland “fight or flight” hormone elicits a release of glucose storage in liver in times of stress Gives a burst of energy If CHO is not eaten body devours its own protein If blood regulation fails diabetes & hypoglycemia may occur 9. Types of diabetes and characteristics of each, diet control Type I diabetes: (hyperglycemia) disorder of blood glucose regulation juvenile onset Insulin dependent diabetes mellitus (IDDM) Injection of insulin; cannot take orally Pancreas unable to synthesize insulin Type II diabetes: Most common Adult onset cells are resistant to insulin obesity Diet Control: Type I diet, exercise, & insulin CHO counting Provide even amounts of CHO Diet control: Type II Weight control CHO counting Provide even amounts of CHO Fat intake→ decrease unless mono- fats 10. Chemical structure of fats Triglycerides composed of 95% lipids; 3 fatty acids + backbone (glycerol); series of reactions Saturated fat full of hydrogens Unsaturated fat missing hydrogens **Omega-3 & Omega-6 fatty acids 18 carbon polyunsaturated fatty acids 11. Types of fats- saturated, poly, mono- ; omega 3 and omega 6-know sources of each and health consequences of each Saturated= solid & more firm Stearic acid; 18 carbon butter, lard, palm & coconut oils Unsaturated= liquid & less firm Polyunsaturated= linoleic; 18 carbon omega-3 & omega-6 vegetable oil Monounsaturated= oleic; 18 carbonolive, canola, & peanut oils; avocado Number of bonds Sat fats= NO double bonds Mono FAs= 1 double bond Poly FAs= 2 or more double bonds Linoleic and linolenic (poly FAs) Linoleic= 18 carbon w/ 2 double bonds; Omega- 6 **Found in sunflower, safflower, corn & soybean oil; meats 5-10% of daily energy Linolenic= 18 carbon w/ 3 double bonds; Omega- 3 ** Found in fish (salmon), flaxseed, soybean, canola, & walnut oil **Essential to normal growth & development 0.6-1.2% of daily energy **May treat/prevent heart disease, hypertension, cancer & arthritis ** EPA & DHA human milk, fish & shellfish 12. Know about hydrogenation/saturation: what are advantages and disadvantages, know the chemistry. Hydrogenation= adding hydrogens; more hydrogens means more saturation Advantages increases shelf life (preservation) & consistency Disadvantages raises LDL cholesterol; higher risk of cardiovascular diseases, diabetes & atherosclerosis **No more than 7% of daily kcal intake 13. Know about cis and trans fats- health consequences Cis- fatty acid has its hydrogens on the same side of the double bond Cis molecules bend into U shape Naturally occurring unsaturated FAs Trans- fatty acid has its hydrogens on the opposite sides; more linear Occurs in partially hydrogenated foods configuration from cis to trans Trans-fats raise LDL & lower HDL development of Coronary heart diseases Omega 3 fatty acids lower cholesterol and heart disease 14. What is a phospholipid, what does it do, examples Phospholipid= similar to TG but have a phosphate group w/ a molecule of choline in place of one of the FAs 1. Part of cell membranes Lecithin is best known tablets are broken down by enzymes Made by liver Often taken as supplement 9 kcals per gram Destroyed by lecithinase when taken orally 2. Solubility in fat & water FAs make phospholipids soluble in fat Phosphate group allows solubility in water Emulsifiers in food industry candy bars, mayonnaise Naturally in eggs, soybeans, liver, peanuts, & wheat germ 15. Cholesterol in foods, in the body/blood, recommended amounts in diet LDL= < 130 Optimal LDL= < 100 HDL= > 45 Optimal HDL= > 60 Total cholesterol= <200 TG= 20% or 150 1. Atherosclerosis- accumulation of plaques in lumen of artery Stiffen & narrow arteries Diet high in saturated fat raises LDL causing plaque formation 2. Thrombosis- large clot blocks off a blood vessel Platelets cause blood clots; treated as site of injury Coronary & cerebral thrombosis 3. Embolism- clot breaks free & travels until it gets stuck in smaller artery Omega 3 protects against clots Cholesterol only harmful when excess amounts deposit in artery walls causing atherosclerosis AHA recommends 300 mg or less per day 16. Know how fats are digested, absorbed, and transported. Know the transport vehicles FAT digestion: Fats= hydrophobic & separate from water-based digestive juices Lingual lipase is secreted in the mouth Gastric lipase access & hydrolyzes small amount of fat in the stomach CCK in the SI gallbladder releases bile bile acts as emulsifier Pancreatic lipase in SI flows in Emulsified fat (TG) Monoglycerides, glycerol, & FAs are absorbed in SI ABSORPTION: TG are hydrolyzed; Monoglycerides & long chain FA merge into spherical complexes – micelles (tiny) fit between villiabsorbed The glycerol and short chain FA do not form micelles absorbed into bloodstream Large lipids form micelles that diffuse into intestinal cells reassembly of TG; chylomicrons formed (proteins) TRANSPORT: TG and other large lipids are clustered together in intestinal cells to form a lipoprotein called a chylomicron Transported via lymph and enter the bloodstream close to the heart Chylomicrons transport fats to all cells of the body which remove what is needed, leaving a remnant to be recycled by the liver 4 types of Lipoproteins: 1. Chylomicrons Largest & least dense Transport diet-derived lipids Liver removes remnants from blood 2. Very low density lipoproteins (VLDL) Made in liver Proportion of lipid shift ½ TG 3. Low density lipoproteins (LDL) “bad cholesterol” Cell needs Liver regulation ½ cholesterol implication of heart disease; high risk of heart attack Recommended amts: < 130 mg/dl 4. High density lipoproteins (HDL) “Good cholesterol” Removes cholesterol from cells; protective effect (heart attack) Carries cholesterol to liver for recycling Anti-inflammatory properties ½ protein Recommended amts: >45mg/dl 17. Know about HDL, LDL-risk of disease; how to raise levels/decrease levels HDL increased by: monounsaturated fats, soluble fibers, exercise, weight control, & antioxidants LDL increased by: saturated fats; found in meats, whole milk products, & tropical oils Avoid hydrogenated food for trans-fat
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'