Nutrition- topic 1

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Nutrition- topic 1
2012-10-29 11:08:01
Nutrition topic

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  1. What are the abundant elements of life?
    Carbon, hydrogen, nitrogen, oxygen, phosphorous
  2. What are the trace elements?
    Calcium, chlorine, cobalt, coppers, iodine, iron, manganese, magnesium, potassium, sodium, sulohur, selenium, zinc
  3. What are the detectable elements?
    Boron, bromine, chomium, molubdenum, silicon, tin
  4. What are the macromolecules?
    carbohydrats, proteins, nucleic acids, lipids
  5. What are carbohydrates?
    Polymers of simple sugars
  6. How do nutrients effect genes?
    A nutrient an interact with cellular machinery and influence the ay the cell uses the nutrient
  7. What is the lac operon of e. coli?
    Lac operon is found in e. coli which turns on genes to process lactose
  8. When does a cell need an increase in nutrients?
    When a cell is growing, it needs an increase in the concentration of nutrients
  9. What is the N-terminus?
    N-terminus corresponds to the 5' end of a gene
  10. How many standard amino acids are there?
  11. How are nucleic acids linked together?
    phospho-diester link
  12. How does our body use nucleic acids?
    Maintained in permanent storage
  13. What are lipids composed of?
    Composed of fatty acids, cholesterol, and others
  14. What is the functional classification of lipids?
    Lipids are a diverse set of organic compounds that are not soluble in water but are soluble in organic solvents (such as alcohol or ether)
  15. What is lauric acid?
    • dodecanoic acid
    • C12:0
  16. What is myristic acid?
    • tetradecanoic acid
    • C14:0
  17. What is palmitic acid?
    • hexadecanoic acid
    • C16:0
  18. What is stearic acid?
    • octadecanoic acid
    • C18:0
  19. What is palmitoleic acid?
    • 9-hexadecanoic acid
    • C16:1- n-7 cis
  20. What is oleic acid?
    • 9-octadecanoic acid
    • C18:1, n-9 cis
  21. What is elaidic acid?
    • 9-octadecanoic acid
    • C18:1, n-9 trans
  22. What is linoleic acid?
    • 9,12-octadecadienoic acid
    • C18:2, n-6,9 all cis
  23. What is alpha-linolenic acid?
    • 9,12,15- octadecatrienoic acid
    • C18:3, n-3,6,9 all cis
  24. What is gamma-linolenic acid?
    • 6,9,12- octadecatrienoic acid
    • C18:3, n-6,9,12 al cis
  25. What is columbinic acid?
    • 5,9,12- octatrienoic acid
    • C18:3, n-6 cis, 9 cis, 13 trans
  26. What is arachidic acid?
    • eicosanoic acid
    • C20:0
  27. What is behenic acid?
    • docosanoic acid
    • C22:0
  28. What is eicosenoic acid?
    • 11-eicosenoic acid
    • C20:1, n-9 cis
  29. What fatty acid is olive oil rich in?
    • oleic acid
    • C18:1
  30. What fatty acid is saddlower oil rich in?
    • linoleic acid
    • C18:2
  31. What fatty acid is lard, beef tallow rich in?
    Rich in palmitic (C16:0) and stearic (C18:0)
  32. How can you easily tell the relative number of double bonds in a fat?
    State at room temperature
  33. What are the different uses of fatty acids?
    • Energy source
    • Structural component
    • Subtrate for the synthesis of signaling molecules
    • Covalend modification of proteins
  34. What are triacylglycerols?
    A glycerol with 3 fatty acids
  35. Which cells in the body can make cholesterol?
    • Every body in the body has the ability to make cholesterol¬†
    • Begins with acetyl-CoA
  36. What does colesterol look like?
    Long and flat
  37. What does cholesterol do to arteries?
    Makes them stiff
  38. What is the key enzyme needed for synthesis of cholesterol?
  39. Can cholesterol be oxidized to produce energy?
    No, the formation of cholesterol is not reversible
  40. What is cholesterol a precursor for?
    Highly bioactive molecules
  41. What are 3 different uses for cholesterol?
    • Substrte for the synthesis of steroid hormones and vitamin D
    • Substrate for the synthesis of bile acids
    • Required for control of membrane fluidity
  42. How does cholesterol affect membrane fluidity?
    • The more cholesterol in the membrane, the more fluid it is
    • If the membrane is too rigid, proteins cant move and it wont work
  43. Why does cholesterol build up in the body?
    It cant be destroyed
  44. What does our body do with an excess of cholesterol?
    Synthesize it into cholesteryl esters
  45. What is inactive cholesterol?
    • When it is esterified it is metabolically inactive (lipid droplet)
    • Once there is a need for cholesterol it liberates the fatty acid and the cholesterol is free to use
  46. What is a nutrient?
    A nutrient is either a chemical element or compound that is used in the metabolic processes of, or forms an integral component of the physiology of an organism
  47. What is a macro nutrient?
    A nutrient needed in large quantities
  48. What is a micro nutrient?
    A nutrient needed in smll quantities
  49. What are the different uses of nutrients?
    Some nutrients are used as energy sources, or used to build structures; others provide support functions in metabolism
  50. What are the 3 macronutrients?
    • carbohydrates
    • proteins
    • fats
  51. What are 2 types of micronutrients?
    • Minerals
    • Vitamins
  52. What are micronutrients typically used for?
    Typicall act as co-substrates, or as enzyme cofactors which determine enzymatic activity
  53. What is an essential nutrient?
    the absoence of the nutrient from the diet results in characteristic signs of a deficiency disease and these signs are prevented only by the nutrient itself or a specific precursor of it
  54. What are the essential amino acids?
    • Isoleucine
    • Leucine
    • Lysine
    • Methionine
    • Phenylalanine
    • Threonine
    • Tryptophan
    • Valine
    • Histidine
    • Arginine (in children and special cases)
  55. What are essential fatty acids?
    Humans cannot make fatty acids th double bonds between carbons located at position 8 or less (counting from the methyl end)
  56. What are 2 essential fatty acids?
    • linoleic acid (C18:2 n-6)
    • Linolenic acid (C18:3 n-3)
  57. What are the essential faty soluble vitamins?
    A, D, E, K
  58. What are the essential water-soluble vitamins?
    B1, B2, B3, B6, B5, B9, B12, B7, C, Choline
  59. What are the uses for choline?
    • Substrate for phosphatidylcholine biosynthesis
    • Ensures the structural integrity and signaling functions of cell membranes
    • Source of methyl groups
    • Used to make a variety of very important metabolites
  60. What is the substrate for phosphatidyl choline biosynthesis?
  61. What is phosphatidylcholine?
  62. What is the de novo synthesis of choline?
    • Three sucessie methylations of the phosphatofulethanolamine headgroup generates phosphatylcholine
    • Choline can be released from phosphatidylcholine
  63. What are the essential macrominerals?
    Calcium, chloride ion, phosphorous, potzssium, magnesium, sulphur
  64. What are the essential trace minerals?
    Cobalt, copper, fluoride ion, iodine, iron, manganese, nickel, sodium, selenium, zinc
  65. What are phytochemicals?
    a broad and diverse group of plant derived compounds
  66. What are flavonoids?
    a subclass of phytochemicals throught to have beneficial effects on health
  67. What are essential fatty acids for?
    • EFAs are substrates for a class of molecules in the body called eicosanoids (prostaglandins, leukotrines, and thromboxanes)
    • EFAs are important in immune function, inflammatory respose, blood clotting, vasodilation, kidney function, conitive function
  68. What happens with essential fatty acid deficiency?
    Growth retardation, sparse hair growth, dry skin and scaling (excema), general weakness, depression, poor wound healing, increased susceptibility to infection, edema, vision problems; neurologic problems (severe cases)
  69. What happens with essential fatty acid excess?
    • Does not appear to cause severe problems
    • May cause excessive bleeding (slow blood clotting)
  70. Where is vitamin A found?
    brightly colored fruits and vegetables
  71. What is vitamin A essential for?
    Essential for proper maintenance of epithelial cells; deficiency of this vitmain causes mucus-secreting cells to be replaced by keratin producing cells, leading to zerosis (abnormal dryness)
  72. Which vitamin primarily affects eye function and how?
    • Vitamin A
    • Deficiency can cause night blindness, eye xerosis which causes ulcerations and eventually leading to blindness
  73. Why are people with diseases involvinv the absorption of lipids at risk for vitamin A deficiency?
    Vitamin A is a fat soluble vitamin
  74. What are some side effects of vitamin A excess?
    • Birth defects
    • Reduced bone mineral density
    • Weight loss, headache, vision problems, dry itchy skin, hair loss, anemia, teeth discoloration, enlarged liver and spleen
  75. What is iron?
    A transition metal; classified as a 'micromineral'
  76. How is iron used in the body?
    used as a prosthetic group by maby biologically important proteins eg. heme groups of hemoglobin, myoglobin, cytochrome c, peroxidases, hydroxylases, generally found in enzymes involved in carrying or metabolizing oxygen
  77. How much iron does the average person contain>
    • approx 3-4 grams
    • about 60% of this amount in found in blood
  78. How do we lose iron?
    shedding of epitherlial surfaces, through intestine (occult blood loss), menstruation, lactation
  79. What are the signs of iron deficiency?
    Amenia, low bloor idon: pale skin, tired and weakness, difficulty maintain body temperature, shortness of breath, an inflamed tongue, diminished cognitive function, decreased immune function
  80. Who are at most risk for iron deficiency anemia?
    Alcoholics, patients with infectious, inflammatory, or neoplastic diseases (cancer)
  81. What is iron toxicity with genetic basis?
    African hemochromatosis, porphyria, hyperferritinemia, heriditary hemocromatosis
  82. What is secondary hemochromatosis?
    Caused by excessive alcohol consumption; excessive use of dietary iron supplements
  83. What is iodine essential for?
    • Necessary for normal thyroid function
    • Essential substrate for the synthesis of thyroid hormones
  84. What are thyroid hormones used for?
    Conrol many aspects of energy (carbohydrate and fat) metabolism; ligants of TR receptor (a transcription factor belonging to the nuclear receptor superfamily of transcription factors)
  85. What are some sources of iodine?
    Seafood, kelp, dairy products,; most common 'modern' source is iodized table salt
  86. What are some side effects of iodine deficiency?
    Increased fetal and infant mortality, neurological defects and mental retardation (cretinism), decreased reproductive fitness, hypothyroidism, goiter (hypertrophy of the thyroid gland)
  87. What are some secondary thyroid related disorders?
    Anemia, arthritis, eye enlargement, and inflammation, hair loss and premature graying of hair; inflammatory bowel diseases, depression
  88. What are goiters caused by?
    • Caused by iodine deficiency; impaired thyroid hormone synthesis
    • Also caused by excessive iodine, which results in the inhibition of thyroid hormone production
  89. What are some side effects of iodine excess?
    • Skin ulceration ('kelp acne', high incidence in Japan where kelp is consuemed in large quantities)
    • Impairs thyroid hormone production and causes goiter in response to decreased thyroid hormone concentration
  90. What is the purpose of a lipocyte?
    To store fat until it can be used for energy
  91. Do adipocytes die?
    No, they just get smaller
  92. Which cells typically produce cholesterol?
    liver cells
  93. Where do we get cholesterol from in our diet?
    Meat and dairy products
  94. What are some problems with nutrient processing?
    • Inborn errors of metabolism
    • Acquired metabolic syndromes
  95. What determines how individuals percieve bitter taste?
    Variateions in bitter taste receptors
  96. What is lactase?
    An enzyme produced by the intestine that digests lactose
  97. Why is lactose intollerance so common?
    Because milk is not naturally consumed by adults
  98. What is LCT gene?
    • encodes lactase
    • expression normally shits down after weaning
  99. What gene variation determines lactose intollerance>
  100. What gene is thought to be respinsible for the absorption of dietry cholesterol in the intestine?
  101. What can cholesterol import be inhibited by?
    Cholesterol import can be inhibited by ezetimibe, a drug that interacts with NCP1L1