Test 3 Flashcards

Question

Types of amino acids

Answer 1

9 essential amino acids * Cannot be made by the body * It is essential to obtain them from diet 11 nonessential amino acids * Can be synthesized by the body from other amino acids or by adding nitrogen to carbon-containing structures Conditionally essential amino acids. * Under certain conditions, some nonessential amino acids cannot be made by the body - stress, diseases, babies

Answer 2

Peptide bonds hold amino acids together. * Acid amino group of one acid connected to the amine group of another amino acid * 2 amino acids= dipeptide; 3 amino acids = tripepetide. * Many amino acids= polypeptide Protein may contain 100-10,000 amino acids. * Form specific 3D shapes due to interactions between side chains of amino acid * 3D shape is critical to protein function

Answer 3

Unfolding of protein shape by heat, acids, bases or salts - SHAKING. Start loosing shape * Change of protein shape alters its function 1. Examples: cooking meat, eggs change texture 2. stomach acid untangles protein to aid in digestion

Answer 4

Dietary proteins are digested and absorbed in the stomach and small intestine * Stomach acids denature protein 1. Active pepsin, which breaks down protein into shorter polypeptides. * In the small intestine, polypeptides broken down into tri, dipeptides and amino acids * Amino acids enter the blood and travel to the liver

Answer 5

* Diet * breakdown of proteins in the body * A limited supply is stored in "amino acid pools" in blood and cells for needed protein synthesis

Answer 6

process of continuous breakdown and synthesis of protein from its amino acids

Answer 7

Amino acids are used to make: * Body protein * non-protein sunstances 1. examples: thyroid hormone, melanin After amino groups removed, converted to urea, excreted in urine, amino acids can also be: * burned for energy * stored as fat * made into glucose

Answer 8

* DNA in the cell nucleus contains instructions for protein synthesis * Gene: DNA segment that codes for specific protein * Specialized RNA molecules carry out instructions for protein synthesis * Gene mutations can result in errors in protein synthesis. 1. Example: sickle-cell anemia * only one amino acid out of place makes hemoglobin carry only 30 instead of 40

Answer 9

* Protein quality varies among food sources 1. Depends on digestibility and amino acid profile * Complete proteins contain all the essential amino acids along with the nonessential one 1. Examples: animal protein, soy protein * Incomplete proteins are low in one or more essential amino acids 1. Example: plant food

Answer 10

Plant proteins "upgraded" to complete proteins by: * Consuming modest amounts of soy or animal protein, or * Being complemented with other plant proteins which provide enough of the limiting amino acid Protein Digestibility Correct Amino Acid Score (PDCAAS) * Measure of protein quality taking into account digestibility and amino acid profile * Basis of protein as % daily value on foods

Answer 11

* Nitrogen Balance: Amount of protein consumed = amount of protein used. * Nitrogen Imbalaces: 1. Positive Nitrogen Imbalance: more nitrogen is retained (for protein synthesis) than is excreted Examples: infants, children, pregnant women 1. Negative Nitrogen Balance: more nitrogen is excreted than consumed (body protein broken down) Examples: starvation, serious injury or illness

Answer 12

DRI * 10-35% of total daily calories from protein * Average intake is 15% Calculating daily protein needs: * Convert weight to pounds by dividing by 2.2 * weight in kg x 0.8g = protein daily intake in gr.

Answer 13

Eating too much protein: * Can increase risk of heart disease, kidney stones, calcium loss from bones. * Can displace other nutrient- and fiber rich foods associated with reduced risk of chronic diseases: 1. Whole grains fruits and vegetables. Eating too little: * Low protein diets associated with loss of bone mass Protein Energy Malnutrition (PEM) * Inadequate calories and/or proteins * More common in children, because they are growing * Factors: poverty, poor quality food, insufficient food, unsanitary living conditions, ignorance, stopping lactation too early

Answer 14

* Kwashiorkor: severe deficiency of dietary protein 1. Seen in children weaned to low-protein cereals * Marasmus: severe defiency of calories 1. Signs: emaciation, lack of growth, loss of fat stores * Marasmic Kwashior: worst of both conditions 1. Medical treatment and food: three step approach - LOST OF ORGANS

Answer 15

* Variety of plant foods * Protein rich meat alternatives 1. Soy 2. Dried beans and legumes 3. nuts 4. eggs and dairy (lacto-ovo- vegetarians)

Answer 16

* high quality protein source * low in saturated fat * contains isoflavones (phytoestrogens) 1. May have anticancer functions 2. May relieve menopausal symptoms' * Lowers blood cholesterol levels * may reduce risk of heart disease, certain cancers

Answer 17

* edamame * tofu * soy milk soy flour tempeh * miso * soy meat analogs texture soy protein

Answer 18

Benefits: * May reduce risk of heart disease, high blood pressure, diabetes, cancer, stroke, obesity Risks: * Potential deficiencies of nutrients found in animal foods 1. Protein, iron, zinc, calcium, vitamin D, riboflavin, vitamin B12, and A, Omega 3 fatty acids

Answer 19

They are essential nutrients * tasteless, organic compounds needed in small amounts * a deficiency will cause physiological symptoms * Consuming too much of some vitamins will cause adverse effects

Answer 20

Fat-soluble * Are absorbed with dietary fats * Can be stored in body * Vitamins A,D.E,K Water soluble * Absorbed with water * Not stored in the body, but excess still harmful

Answer 21

Proper food preparation techniques can reduce loss. * Don't expose produce to air * A little water is enough 1. Water soluble vitamins leech into the water * Reduce cooking time 1. Microwave, steam, or stir fry vegetables until just tender * Refrigeration delays vitamin loss

Answer 22

retinoids (retinol, retinal, retinoic acid) * Performed vitamin A only found in animal foods: liver, eggs, fortified milk, cheese * Some plants contain provitamin A carotenoids, which are converted to retinol in the body. 1. Carotenoids, including beta-cartotene, are pigments which give color to carrots, cantaloupe, sweet potatoes, spinach and broccoli

Answer 23

* Essential for healthy eyes * Involved in cell differenctiation, reproduction and immunity by promotig gene expression for: 1. Healthy skin 2. bone growth 3. fetal development 4. white blood cells to fight harmful bacteria

Answer 24

Too much * Excessive amounts of preformed vitamin A can accumulate to toxic levels * Carotenoids in foods are not toxic * Excess of Carotenoids can cause nonthreatening condition: CAROTENODERMIA Too litlle * Chronic vitamin A deficiency causes night blindness * #1 cause of preventable blindness in children in developing country * Associated with stunting of bone

Answer 25

Alpha-tocopherol is most active form in body FUNCTION: * Act as a powerful antioxidant 1. Protects cell membranes, prevents oxidation of LDL cholesterol * acts as an anticoagulant, inhibiting formation of harmful clots inside bloodstream FOOD SOURCES: vegetable oils, nuts, seeds, fortified cereals, some green leafy vegetables

Answer 26

Too much: * No problems if overconsuming vitamin E naturally * Synthetic overconsumption, increases the risk of hemorrhage Too little: * Although rare, chronic deficiency of vitamin E can cause nerve problems, muscle weakness, and free radical damage to cell membrane

Answer 27

Two forms: * Menaquinone synthesized by intestinal bacteria * Phylloquinone found in green leafy plants FUNCTIONS: * Essential for blood clotting 1. involved in four blood clotting factors * Important for bone health 1. Enables bone protein osteocalcin to bind with calcium FOOD SOURCES: green vegetables such as broccoli, aspargus, spinach, salad greens, brussels sprouts, cabbage; also vegetable oils and margarine, green tea

Answer 28

Too much: * No problems of over consuming vitamin K * People taking anticoagulant medications such as Warfin need to keep vitamin K intake consistent 1. Changes in intake can increase or deacrease drug effectiveness Too little: * May affect blood clotting, but is extremely rare 1. At risk: people with problems absorbing fat.

Answer 29

* Cholesterol- cointaing coumpound in skin is converted to inactive form of vitamin D * People with insufficient sun exposure must meet needs through diet; vitamin D in foods is also in inactive form * Inactive form converted to circulating form in liver to active form in kidneys

Answer 30

* Regulates two important bone minerals: calcium, phosphorus 1. Stimulates intestinal absorption of Ca and P to maintain healthy blood levels and build and maintain bones 2. When dietary calcium is inadequate, vitamin D and parathyroid hormone cause calcium to leave bones to maintain necessary blood levels * May prevent type 2 diabetes and some cancers FOOD SOURCES: fortified milk, and yogurt, fortified cereals, fatty fish (sardines, salmon, tuna)

Answer 31

Too much: * Overuse of supplements may lead to hypervitaminosis D, which causes hypercalcemia. 1. Damaging calcium deposited in kidneys, lungs, blood vessels, heart. Too little: * Rickets: vitamin deficiency in children 1. On the rise in the US due to decresead milk consumption 2. the bones of children with rickets aren't adequately mineralized with calcium and phosphorus, causing them to weaken and leading to bowed legs. * Ostemalacia: adult equivalent of rickets

Answer 32

Are water soluble, not stored in body * excess excreted in urine * however routine intake of excessive amounts can be harmful Vitamin B * share common role as coenzymes 1. help many enzymes produce chemical reactions in cells Enzymes: speeds up reactions, makes sure reactions will occur

Answer 33

Vitamin B1 FUNCTIONS: * Transmission of nerve impulses, electrical and quemical * Metabolism of carbohydrates and certain amino acids * plays a role in breakdown of alcohol in bidy FOOD SOURCES: enriched and whole grain products, pork

Answer 34

Too much: * Not toxic Too little: * Beriberi: thiamin deficiency disease (loss of appetite, weight, memory, confusion) * Rare in the US, due to enriched grains * Chronic alcohol abuse can lead to advanced form: Wernicke-Korsakoff syndrome, progressively damaging brain disorder 1. Due to thiamin-deficient diet, and alcohol interferes with thiamin absorption

Answer 35

Vitamin B2 Light-sensitive vitamin, abundant in milk * Opaque containers preserve riboflavin content FUNCTIONS: * Important for energy metabolism * keeps cells healthy * Enhances functions of other B vitamins, such as niacin and B12 FOOD SOURCES: milk, yogurt, enriched cereals and grains

Answer 36

Too much: * Excess riboflavin excreted in urine: bright yellow color Too litlle: * Deficiency symptoms rarely seen in healthy individuals eating a balanced diet 1. Sore throat, swelling inside mouth, inflamed and purplish- red tongue, dry and scaly lips

Answer 37

Vitamin B3 Active forms: nicotinic and nicotinamide FUNCTION: * neeeded for energy metabolism * synthesize fat and cholesterol * keep skin cells and digestive system healthy Sometimes prescribed in high doses by physicians to decrease blood cholesterol LDL and triglycerides, increase HDL Can be made in the body from the amino acid tryptophan: daily needs expressed in niacin equivalents NE Tryptophan: stimulates the production of HDL makes you fall asleep (turkey) FOOD SOURCE: meat, fish, poultry, enriched whole grain breads, fortified cereals * Protein rich foods are a good source of tryptophan

Answer 38

Too much: * niancin supplements can cause flushing, nausea, vomiting, be toxic to liver, raise blood glucose levels - DESTROY LIVER- Too little: * Pellagra: known as four Ds 1. dermatidis, diarrhea, dementia, death 2. once common in the south due to corn based diet

Answer 39

FUNCTIONS: * works as coenzymes for over 100 enzymes in protein metabolism, needed to: 1. Make nonessential amino acids, convert tryptophan to niacin and hemoglobin in red blood cells 2. Keep immune and nervous system healthy 3. Metabolize fats and carbohydrates and break down glycogen FOOD SOURCES: Meat, fish, poultry, fortified cereal (no bread), nuts, legumes, peanut butter, many fruits and vegetables

Answer 40

Too much: * Nerve damage Too little: * Sore tongue, skin inflammation, depression, confusion, anemia * Those with alcoholism at risk for deficiency due to poor diet and alcohol causes body to lose B6

Answer 41

Vitamin B9 * Naturally occuring form in foods * Folic acid: synthetic form of folate added to foods and supplements FUNCTIONS: * Vital for DNA synthesis 1. To create and maintain new cells, including red blood cells 2. to help body use amino acids 3. reduces risk of some cancer FOOD SOURCES: enriched grains, legumes, broccoli, aspargus, leafy greens such as spinach

Answer 42

Too much: * Too much folic acid makes vitamin 12 deficiency anemia Too little: * During pregnancy can result in neutral tube birth defects * Folate deficiency can lead to macrocytic anemia cytic= cells vegetarians eat a lot of B9, so they are more prone to macrocytic anemia

Answer 43

Also known as COBALAMINE, because it contain cobalt * Requires instrict factor protein made in stomach, in order to be absorbed in small intestine 1. Pernicious anemia results in people who cannot make intrict factor: treatment requires B12 injection to bypass intestine 2. Symptoms may take years to appear since B12 is stored in liver Instrict factor: synthesis and absorption of protein

Answer 44

* To make DNA * To use certain fatty acids and amino acids * For healthy nerves and cells, especially red blood cells FOOD SOURCES: * Only found in animal products, meat, fish, poutry and dairy * Syhthetic B12 is found in fortified foods such as soy milk and some cereals

Answer 45

Too much: * Not toxic, no UL Too little: * Macrocytic anemia, because folate can't be utilized properly * Lack of instrict factors cause pernicious anemia, involves nerve damage

Answer 46

Ascorbic acid FUNCTIONS: * coenzyme to synthesize and use certain amino acids 1. Needed to make collagen, most abundant protein in body, present in connective tissue. - Important for healthy bones, skin, blood vessels, teeth 2. Also acts as an antioxidant 3. Helps absorb iron from plants 4. breaks down histamine, cause of inflammation.

Answer 47

Too much: * nausea, stomach cramps, diarrhea * Peple with history of kidney stones or hemochromatosis (body stores too much iron) should avoid excess Too little: * Scurvy: inflammation skin and gums

Test 3 Flashcards

(73 cards)