Biochem 11 +12

Card Set Information

Biochem 11 +12
2013-04-10 00:51:20
biochem 11 12

biochem 11 and 12
Show Answers:

  1. 1) Fatty acid groups are referred to as ________ groups.

    A) Acetyl
    B) Acyl
    C) Prenyl
    D) Isoprenoid
    E) Isopentenyl
  2. 2) The double bonds in naturally occurring fatty acids are usually _______ isomers.

    A) Cis
    B) Trans
    C) Both cis and trans
    D) Essential
    E) Nonessential
  3. 3) The essential fatty acids are

    A) Arachidonic acid
    B) Linoleic acid
    C) Linolenic acid
    D) Both A and B are correct
    E) Both B and C are correct
  4. 4) Fatty acids react with alcohols to form _____.

    A) Amides
    B) Ethers
    C) Anhydrides
    D) Epoxides
    E) Esters
  5. 5) Prostaglandins are involved in _________.

    A) Ovulation
    B) Inflammation
    C) Digestion
    D) Both A and B are correct
    E) All of the above are correct
  6. 6) The functions of fat include

    A) Insulation
    B) Energy storage
    C) Water-repellent properties
    D) Both A and B are correct
    E) All of the above are correct
  7. 7) Waxes

    A) Are complex mixtures of nonpolar lipids
    B) Are esters formed from long-chain fatty acids and long-chain alcohols
    C) Contain hydrocarbons, sterols, and alcohols
    D) Both A and B are correct
    E) Both A and C are correct
  8. 8) Phospholipids are

    A) Structural components of membranes
    B) Surface active agents
    C) Rich energy sources
    D) Both A and B are correct
    E) All of the above are correct
  9. 9) Phosphatidylcholine is sometimes referred to as ______.

    A) PIP2
    B) Cephalin
    C) Ceramide
    D) Cardiolipin
    E)None of the above are correct
  10. 10) The myelin sheath 

    A) Surrounds nerve cell axons
    B) Contains large amounts of cardiolipin
    C) Facilitates nerve impulse transmission
    D) Both A and B are correct
    E) Both A and C are correct
  11. 11) All of the following are glycolipids except _________.

    A) Sulfatides
    B) Cerebrosides
    C) Gangliosides
    D) Both A and B are correct
    E) None of the above are correct
  12. 12) The role of very low density lipoproteins is

    A) Scavenging the cholesterol from cell membranes
    B) Transporting of lipids from liver to tissues
    C) Transporting of cholesterol esters to the liver
    D) Both A and B are correct
    E) All of the above are correct
  13. 13) Which of the following statements concerning carotenoids is not true?

    A) Carotenoids are the only examples of the monoterpenes
    B) The carotenes are hydrocarbon members of the carotenoids
    C) Xanthophylls are oxygenated derivatives of the carotenes
    D) Carotenoids are orange-colored pigments
    E) None of the above are true
  14. 14) Which of the following molecules is not a lipid?

    A) Fatty acids
    B) Steroids
    C) Isoprenoids
    D) Waxes
    E)  All of the above are lipids
  15. 15) The basic structure of biological membranes is a consequence of the physical properties of  _______.

    A) Proteins
    B) Phospholipids
    C) Cholesterol
    D) Water
    E) None of the above are correct
  16. 16) A membrane’s fluidity is largely determined by the percentage of 

    A) Phosphatidyl choline
    B) Phosphatidylethanolamine
    C) Fatty acids
    D) Cardiolipin
    E) Unsaturated fatty acids
  17. 17) In the fluid mosaic model of membrane structure

    A) Proteins form an inner layer between two layers of lipid
    B) Proteins coat an inner layer of lipids
    C) Proteins float in a lipid bilayer
    D) Proteins are covalently bonded to the lipid bilayer
    E) All of the above are true
  18. 18) Which of the following statements concerning the anion channel protein is not true?

    A) It plays an important role in carbon dioxide transport in blood
    B) It facilitates the chloride shift
    C) Bicarbonate and chloride exchange occurs through the anion channel protein
    D) The N-terminal methionine residue of the anion channel protein is prenylated
    E) All of the above statements are true.
  19. 19) Energy requiring transport mechanisms include

    A) Primary active transport
    B) Diffusion
    C) Facilitated diffusion
    D) Both A and B are correct
    E) Both A and C are correct
  20. 20) In simple diffusion a solute

    A) Is propelled by random molecular motion
    B) Moves up its concentration gradient
    C) Moves across a membrane because of an input of free  energy.
    D) Both A and B are correct
    E) All of the above are correct
  21. 21) Which of the following statements is not true?

    A) Membrane potential is an electrical gradient across a membrane.
    B) A decrease in membrane potential is referred to as membrane depoalarization.
    C) The term repolarization is defined as the reestablishment of the original membrane potential.
    D) The diffusion of potassium ions out of a nerve cell make the inside of the membrane negative.
    E) The sodium channel in muscle and nerve cells is a voltage-gated channel.
  22. 22) In muscle cells, local depolarization caused by acetylcholine binding leads to the opening of the voltage gated _____channels.

    A) Chloride
    B) Potassium
    C) Proton
    D) Sodium
    E) Glucose permease
  23. 23) The function of glucose permease is an example of 

    A) Primary active transport
    B) Secondary active trasnport
    C) Facilitated diffusion
    D) Simple diffusion
    E) None of the above are true
  24. 24) ω-6 Fatty acids

    A) Have a double bond six carbon atoms from the carbonyl end of the chain
    B) Have a double bond six carbon atoms from the methyl end of the chain
    C) Have six double bonds in the molecule
    D) Have three more double bonds than ω-3 fatty acids
    E) Contain six trans double bonds in the molecule
  25. 25) Membrane receptors are transmembrane molecules or molecular complexes that 

    A) Monitor and respond to changes in the cell’s environment.
    B) Bind to hormones or neurotransmitters
    C) Are involved in embryonic and fetal development
    D) Initiate an intracellular response when they bind an appropriate molecule
    E) All of the above are correct
  26. 26) Patients with familial hypercholesterolemia

    A) Possess depressed levels of plasma cholesterol
    B)  Have missing or defective LDL receptors
    C)  Are homozygous or heterozygous for a nonfunctional LDL receptor gene
    D) Have very high levels of serum cholesterol
    E) B, C and D are correct
  27. 27) Indicate which of the following compounds is a endocannabinoid.

    A) Oleic acid
    B)  Arachidonic acid
    C) Anandamine
    D) Prostaglandin
    E) ω-3 Fatty acids
  28. 28) Low fat diets deficient in essential fatty acids are characterized by which of the following?

    A)  Poor wound healing
    B)  Alopecia
    C)  Dental caries
    D Ketone bodies
    E) Both A and B are correct
  29. 29) Which of the following structural features is not characteristic of TXA2 ?

    A) An ether ring
    B) One OH group
    C) Two double bonds
    D) One double bond
    E) Is derived from arachidonic acid
  30. 30) Neutral fats belong to which of the following?

    A) Phospholipids
    B) Glycolipids
    C) Prostaglandins
    D)  Triacylglycerols
    E) Free fatty acids
  31. In addition to the prostaglandins and leukotrienes the autocrine regulators include:

    Arachidonic acid
    Linoleic acid
    All of the above are correct
  32. Choose the lipid class that acts as  surfactants.

    Fatty acids
    Both A and B are correct
  33. Membrane proteins are linked to anchor molecules through a ___________ link

  34. Glycolipids differ from sphingolipids in that they contain no _________.

    Fatty acid
    Both B and C are correct
  35. Which of the following is not likely to be a naturally occurring fatty acid

  36. How many isoprene units does a diterpene contain?

  37. The function of dolichols is to 

    Transport sugars in glycoprotein synthesis
    Bind carbohydrate on the cell surface of bacteria
    Bind to  oxygenated carotenes
    Serve as  precursors of carotenoids
    They are degradation products of steroids
  38. Plasma lipoproteins transport _______ through the blood from one organ to another.

    Cholesteryl esters
    Both A and C are correct
    All of the above are correct
  39. _________ are the principal transporters of cholesteryl esters to tissues.

    Very low density lipoprotein
    Intermediate density lipoprotein
    Low density lipoprotein
    All of the above are true
  40. Individuals with cystic fibrosis have a defective _______ ion channel in their epithelial membrane

  41. A consequence of replacing dietary fat content with sugars is

    No effect on body weight
    An increase in body weight
    A small loss of body weight
    A large decrease in body weight
    An initial loss of weight followed by a large increase in body weight
  42. Which of the following is not a consequence of a low fat diet?

    Low levels of fat soluble vitamins
    Low levels of essential fatty acids
    Brittle hair
    Poor would healing
    Low blood pressure
  43. 43) Phospholipase B hydrolyzes ______ ester bonds in phospholipids

    Both C-1 and C-2
    All of the above
  44. 44)  Which of the following is not a function of phospholipases?

    Membrane remodeling
    Signal transduction
    Energy storage
    Toxic Phospholipases
  45. 45)  Membranes are rigid when they contain

    Large amounts of cholesterol
    Large amounts of unsaturated fatty acids
    Large amounts of saturated fatty acids
    Large amounts of water
    A and B
  46. 46)  Flippase transfers _________ from the outer to inner membrane leaflet

  47. 1. How many acetyl-CoA’s are required to synthesize one molecule of isopentenyl pyrophosphate
  48. 2. ______ is used to transport fatty acids into the mitochondria.
    B-Oxidation and carnitine carrier system
  49. 3)  The b-oxidation of fatty acids requires_________.
    Acyl-CoA, FAD, NAD+, and CoASH
  50. 4. ________, a product of the oxidation of odd-chain fatty acids, is converted to  succinyl-CoA.
  51. 5)   __________ derive a substantial amount of energy from the oxidation of odd-chain fatty acids.
    Ruminant animals (cattle and sheep)
  52. 6) The carbon atoms of cholesterol are derived from _____
    Acetyl CoA
  53. 7) The following reaction requires the presence of beta-hydroxyacyl-CoA dehydrogenase
  54. 8) In animals the function of peroxisomal b-oxidation appears to be
    OX of odd chain fatty acids
  55. 9) The acetyl-CoA derived from glyoxysomal b-oxidation is converted to carbohydrate via the
    citric acid cycle, CO2, NADH, H2O, FADH2, glyoxylate cycle and gluconeogenesis
  56. 10. Refsum’s disease results from a buildup of _________ in nerve tissue.
    phytanic acid
  57. 11) Which of the following is not one of the ketone bodies?
    • B-methyl- glutate
    • Ketone bodies INCLUDE: Excess Acetyl CoA, Acetone, Acetoacetate and Beta-hydroxybutyrate.
  58. 12. Most eicosanoids are derived from either _________.
    arachidonic acid
  59. 13) Glycerol from the hydrolysis of triacylglycerols is transported by the blood to the
  60. 14) The intermediates in fatty acid synthesis are linked through a ______ linkage to ACP.
  61. 15)  Saturated fatty acids containing up to 16 carbon atoms are assembled in
  62. 16) Fatty acid synthesis begins with the carboxylation of acetyl CoA to form
    malonyl COA.
  63. 17) All of the following are enzymatic activities found in fatty acid synthase except
  64. 18)  Desaturation of fatty acids involves
    • ER enzymes
    • Acyl-CoA molecules denatured in ER membrane in precense of NADH, uses ctochrome b5 reductase, cytocrom b5, and o2-dependent desaturases, desaturases in animals
  65. 19)   Which of the following types of fatty acid oxidation produces a dicarboxylic
    alpha oxidation
  66. 20)  The conversion of acetyl-CoA to malonyl-CoA is inhibited by
    epinephrine and phosphorylation
  67. 21) The conversion of acyl-CoA to acylcarnitine is inhibited by
    malonyl COA.
  68. 22) In conjugation reactions
    Amol'cs solubility is increased by convertiting it into a derivative that contains a water soluble group and common examples include amides and esters
  69. 23) Depending on an animal’s metabolic needs, fatty acids may be converted to triacylglycerols, energy or
    membrane synthesis.
  70. 24) Membrane remodeling
    Cells use phospholipases to alter the flexibility of membranes by adjusting the ratio of saturated and unsaturated fatty acids or to replace a damaged fatty acid. Fatty acid removal from a phospholipid is followed by a reacylation reaction catalyzed by an acyltransferase.
  71. 25) The conversion of phosphatidylethanolamine to phosphatidylcholine requires
  72. 26) The sulfatides are synthesized when galactocerebriose  reacts with
  73. 27) __________ is the rate-limiting enzyme in cholesterol synthesis.
    HMG-CoA reductase (HMGR)
  74. 28) The conversion of squalene to cholesterol requires
    NADPH and NADH
  75. 29) Cholesterol is a precursor of synthesis of important metabolites used to
    form bile salt, bile salts, steroid hormones nascent lipoproteins.
  76. 30) Most bile acids are conjugated with
    glycine or taurine.
  77. 31) Which of the following tissues cannot use fatty acids as a fuel?
    Brain cells and RBC cannot use fatty acids as fuels.
  78. 32) Lipolysis is used to:
    • occurs during fasting, vigorous exercise and in response to stress
    • Mobilizes body's fat storage when energy reserves are low
    • Fatty acid binding proteins are responsible for transporting fatty acids into target organelles
  79. Oxidation of the carbon farthest from the carbonyl group of a fatty acid is called
    omega oxidation
  80. 34) In the process of thiolytic cleavage  the following occurs:
    • Thiolase catalyzes a C-alpha and C-beta cleavage
    • An acetyl-CoA molecule is realsed
    • Layroyl-CoA is produced
  81. 35) How many FADH2 molecules would be produced in the oxidation of palmitic acid?
  82. 36) The rate limiting step in fatty acid synthesis is
    acetyl COA Carboxylation to form malonyl CoA
  83. 37)  Which of the following lipids have signaling functions?
    Steroid hormones and prostaglandins.
  84. 38) What form of oxidation is characteristic of branched chain fatty acids
    alpha oxidation
  85. 39) The metabolism of fatty acids is regulated in the short term by allosteric modulators, covalent modification and
  86. 40) The most important mechanism for degrading and eliminating cholesterol is the synthesis of
    bile acids in the ER of liver cells.
  87. 41)   The absorption of triglycerides and other lipid nutrients and their distribution to body tissues is referred to as the
    exogenous pathway
  88. 42)  The pathway in which lipoproteins are transported from the liver to cells is referred to
    endogenous pathway
  89. 43)  Functions of lipids
    • Storage of energy
    • Mmb components 
    • Signaling
    • Protection
  90. The triacylglycerol cycle is :
    A mechanism that regulates the level of fatty acid that are available to the body for the energy generation and synthesis of molecules such as phospholipids.
  91. 45) The principal means of producing glycerol in the body
  92. 46) The recycling rate of triacylglycerols to fatty acids  is inhibited by