NTR 108 EXAM 2 REVIEW b-carotene•can be made into vitamin A by the human body•most of the vitamin A in the human is from b-caroteneVitamin D - bone metabolism, intestinal calcium absorption, kidney calcium reabsorptionF.AMINO ACID METABOLISM1.Transamination Transfer of an amine group from an amino acid to the carbon skeleton to form anew (different) amino acida.Used for1)formation of nonessential amino acidsb.Vitamin B6 is neededIn the absence of Vitamin B6, all amino acids would be essential.2.Deamination Removal of the amine group from an amino acida.Used for1)excretion of amine2)energy production from amino acidb.Vitamin B6 is also needed3.Nitrogen excretiona.Loss of nitrogen in1)Feces (as protein)2)Skin, Hair, Nails (as protein)3)Urine (as urea)b.Excess nitrogen (amine group)1)Synthesized into urea in the liver2)Urea is transported to the kidney and excreted in the urinea.Amino acids1)Structurea)amine groupalways has a Nitrogenb)carbon skeletoncentral carbon with hydrogen (backbone)acid groupThe r-group (side chain): - differentiates one amino acid from another - determines the structure - determines function of the amino acidB.Protein is an essential nutrient1.Essential amino acids (EAA)a.Cannot be made by the bodyb.Must be included in the diet to maintain optimal protein statusc.Provide a source of nitrogen for other compoundsd.Can be used as an energy source2.Non-essential amino acids (NEAA)a.Amino acids that the body is able to make from other substances in the dietb.Provide a source of nitrogen for other compoundsc.Can be used as an energy sourceC.Functions of Proteins1.Structural2.Growth3.Maintenance and repair of body tissues4.Energya)4 kcals/gramb)Secondary role5.Hormone productiona.Insulinb.Glucagonc.CCKd.SecretiBone health: 1.Ascorbic Acid (Vitamin C)a.Definition/classification1)Water soluble vitaminb. Functions1.Immune functiona)Protects WBC from oxidative damage2.Skin and blood vessel healtha)collagen formationb)collagen is a key component of skin and many other tissues3.Increases iron absorption4.Antioxidanta)Protects the lungs, LDL cholesterolb)Regenerates Vitamin EVitamin B6 -d.Antioxidants1.Vitamins A, C, E, b-carotene, seleniumC.Dietary Recommendations for Decreasing Cancer Risk1.High fiber diet2.High intake of fruits and vegetables3.Low fata. Recommend 30% of energy intake4.Moderate alcohol intake5.Calorie Restrictiona.Obesity – excessive estrogen and other hormonesb.Total calorie restriction – less oxidative stress6. Behavior Modification a. Definition: The use of empirically demonstrated techniques to improve behavior b. Need to concentrate on the behavior, not the person c. Identify the problem d. Set realistic goals 1) SMART goals a) Specific, Measurable, Attainable, Relevant, Time-Based e. Define the obstacles that might keep them from changing their behavior How to estimate how many calories a person may need?BMI - what is overweight?- Greater than 30 is obesity2.Chromium - Trace mineral. Used to enhance ability of insulin to move glucose from blood into cellsc.Deficiency sign/symptoms1)Rise in blood glucose levelse.Dietary sources1)Whole grains2)Mushrooms3)Nuts4)Cerealsf.Special notes1)A common supplement is Cr-Picolinate2)Claim enhance muscle mass & reduce body fat(no evidence)Aerobic and anaerobic metabolism for each nutrient - Aerobic happens in the mitochondria while anaerobic happens in cytosol 2.Promoter - Increases cell division, does not cause cancera.Alcoholb.High estrogen levelsc.Dietary fatB.Carcinogenesis1.Carcinogen (initiators)Cancer causing substance (initiates cancer)a.Radiation: sunlight, X-raysb.Carcinogenic chemicals (carcinogens)a)natural and synthetic air pollutantsb)pesticidesc)plant (food) and microbial toxins4.Vitamin Aa.Definition/classification1.Lipid soluble2.Vitamin A3.Carotenoidsa)Considered a phytochemicalb)Many different typesc)Highly colored compound (makes leaves yellow, orange etc.)3.Iodine - Trace mineral. Used to synthesizing of thyroid hormones, regulate body temperature and metabolic ratec.Deficiency signs/symptoms1)Goiter (classic)2)Weakness3)Weight gain4)Mental retardationd.Groups at risk1)Lack of iodized salt intake2)People who live in area with low iodine content(not a problem in US since food comes from many places)e.Dietary sources1)Iodized salt (not very high in sea salt)2)Seafood3)Dairy foodsf.Special notes1)Iodine deficiency during pregnancya) Infant risk of cretinism – mental impairmentb) Major cause of preventable mental retardationWeight loss - how can a person lose 1 lb in a week? When do nutrients requirements increase?- After you hit puberty- pregnancy (lactating B.Protein is an essential nutrient1.Essential amino acids (EAA)a.Cannot be made by the bodyb.Must be included in the diet to maintain optimal protein statusc.Provide a source of nitrogen for other compoundsd.Can be used as an energy source2.Non-essential amino acids (NEAA)a.Amino acids that the body is able to make from other substances in the dietb.Provide a source of nitrogen for other compoundsc.Can be used as an energy sourceProtein Requirement (RDA)a.Adult 0.8g protein x kg body weight/per day3.Vegetarian diets - Pros and consa.Pros1)Low in Saturated fats2)High in fiber3)High in most vitamins4)Phytochemicals5)Rich in low energy density foodsb.Cons1)Low in iron2)Low in calcium3)Low energy and protein density (children)4)Low in protein density (pregnant women)5)Low in Vitamin B12 (Vegans, only)Weight Theories -3.Livera.Amino Acids can be taken up before the rest of body gets a chanceb.Regulates level of amino acids in blood3.Riboflavin Water soluble vitamin, B2. used to transfer of energy to ATPc.Deficiency sign/symptoms1)Weakness2)Dry skina)cracks at corner of mouthb)magenta tongued.Groups at risk1)Alcoholics (excess intake)2)Liver disease3)Diabeticse.Dietary sources1)Enriched flour products2)Milk3)Green leafy vegetables4.Niacin - Water soluble vitamin used to transfer of energy from ATP and formation of Fatty acidsc.Deficiency sign/symptoms1)Pellagra (classic)a.Dermatitisb.Diarrheac.Dementiad.Deathd.Groups at risk1)Alcoholics (excess intake)2)Low protein intakea)can be made from an EAA (tryptophan)e.Dietary sources1)Whole grains2)Enriched flour3)Protein with tryptophanf.Special notes1)Niacin can be used as a hypercholesterolemia drug(lowers blood cholesterol)2)Niacin can be toxic at high levelsa)Flushingb)Liver damage4.Protein Deficiencya. Kwashiorkor (Protein Malnutrition)1. Impaired growth,