Quick Biochemistry - Enzymes (Section 1)

  • 1
    Which compound exhibits the lowest density among the following?
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    (A)
    Chylomicron
  • 2
    What enzyme's activity is inhibited by non-steroidal anti-inflammatory drugs like aspirin?
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    (B)
    Cyclooxygenase
  • 3
    What enzyme catalyzes the synthesis of prostaglandins from arachidonate?
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    (A)
    Cyclooxygenase
  • 4
    What best describes a Holoenzyme?
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    (D)
    All of these
  • 5
    Which enzyme deficiency is associated with Gaucher's disease?
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    (C)
    ẞ-Glucosidase
  • 6
    What enzyme deficiency is the cause of Neimann-Pick disease?
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    (D)
    Sphingomyelinase
  • 7
    Which enzyme is deficient in Krabbe's disease?
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    (C)
    ẞ-Galactosidase
  • 8
    Fabry's disease results from a deficiency of which enzyme?
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    (A)
    Ceramide trihexosidase
  • 9
    Farber's disease is caused by a deficiency in which enzyme?
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    (B)
    Ceramidase
  • 10
    Which synthetic nucleotide analogue is used to prevent immunologic rejection in organ transplantation?
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    (D)
    6-Mercaptopurine
  • 11
    Which of the following is an example of an enzyme that functions outside of a cell?
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    (C)
    Pancreatic lipase
  • 12
    What term describes enzymes that are produced in an inactive state within living cells?
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    (D)
    Proenzymes
  • 13
    Which of the following enzymes is classified as a ligase?
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    (A)
    Succinate thiokinase
  • 14
    Which enzyme listed is an example of a lyase?
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    (B)
    Fumarase
  • 15
    Covalent modification of which amino acid often regulates enzyme activity?
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    (D)
    Serine
  • 16
    What type of enzyme catalyzes the addition or removal of water across a carbon-carbon double bond without breaking the bond?
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    (A)
    Hydratase
  • 17
    According to the 'lock and key' model of enzyme action, what is the relationship between the enzyme's active site and the substrate?
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    (B)
    The active site is complementary in shape to that of substance
  • 18
    In the Lineweaver-Burk plot based on the Michaelis-Menten equation, how are the substrate concentrations typically represented on the x-axis?
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    (C)
    1/S
  • 19
    A sigmoidal curve when plotting substrate concentration against reaction velocity is suggestive of what type of enzyme behavior?
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    (B)
    Co-operative binding
  • 20
    Determine the K value of the enzyme giving the kinetic data as below.
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    (D)
    +0.33
  • 21
    What impact does a purely competitive inhibitor have on an enzyme's kinetic properties?
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    (A)
    Raises the Km without changing the Vmax
  • 22
    If a graph illustrates an enzymatic reaction without inhibition (curve X), which curve would represent competitive inhibition of the same reaction?
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    (A)
    A
  • 23
    What type of enzyme typically does not require an inducer?
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    (B)
    Constitutive enzyme
  • 24
    In which type of enzyme is a measurable inducer typically absent?
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    (B)
    Constitutive enzyme
  • 25
    What is the outcome of reversible non-competitive enzyme inhibition?
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    (D)
    The concentration of the active enzyme is lowered
  • 26
    Regarding reversible non-competitive enzyme activity inhibition:
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    (B)
    The inhibitor reduces the maximum reaction rate achievable with a specific enzyme amount
  • 27
    What is a characteristic of competitive enzyme activity inhibition?
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    (A)
    The inhibitor's structure generally mirrors that of the substrate
  • 28
    In enzyme kinetics, what does Vmax represent?
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    (A)
    The amount of active enzyme
  • 29
    What is the meaning of Km in enzyme kinetics?
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    (A)
    The substrate concentration that results in half-maximal velocity
  • 30
    Which of the following statements describes competitive enzyme activity inhibition?
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    (B)
    Apparent Km is increased
  • 31
    In non-competitive enzyme inhibition, what impact does the inhibitor have on the enzyme's Km value?
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    (C)
    Leaves Km unchanged
  • 32
    What type of enzyme uses oxygen during oxidoreduction reactions as an acceptor of hydrogen atoms?
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    (A)
    Cytochrome oxidase
  • 33
    Which enzyme utilizes a substance other than oxygen as the hydrogen acceptor?
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    (B)
    Succinate dehydrogenase
  • 34
    Which enzyme utilizes hydrogen acceptors as its substrate?
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    (C)
    Catalase
  • 35
    Which of the following enzymes is primarily responsible for linking two substrates?
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    (A)
    Glutamine synthetase
  • 36
    What is the typical optimal pH range for the activity of most enzymes?
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    (B)
    Between 5 and 9
  • 37
    What is the nature of coenzymes?
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    (A)
    Heat-stable, dialyzable, non-protein organic molecules
  • 38
    Which of the following is an example of a coenzyme that transfers hydrogen atoms?
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    (B)
    NAD+
  • 39
    Which of the following is an example of a coenzyme involved in the transfer of chemical groups?
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    (D)
    COA
  • 40
    Cocarboxylase is also known as:
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    (A)
    Thiamine pyrophosphate
  • 41
    Which coenzyme features a non-aromatic heterocycle?
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    (D)
    Biotin
  • 42
    Which coenzyme contains an aromatic heterocycle?
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    (A)
    TPP
  • 43
    What best describes isoenzymes?
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    (A)
    Forms of an enzyme that are chemically, immunologically, and electrophoretically distinct
  • 44
    How can isoenzymes be characterized?
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    (B)
    Enzymes activated by hydrolysis
  • 45
    Regarding the isoenzymes of LDH, which statement is correct?
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    (C)
    They exist in 5 forms based on M and H monomer ratios
  • 46
    What is a typical range for CPK values in blood serum?
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    (A)
    4-60 IU/L
  • 47
    Which factors influence enzyme activity?
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    (D)
    All of these
  • 48
    What is the typical range for GOT activity in blood serum?
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    (B)
    4.0-17.0 IU/L
  • 49
    What is the typical range for GPT activity in blood serum?
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    (C)
    3.0-15.0 IU/L
  • 50
    What is a typical range for serum acid phosphatase activity?
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    (B)
    1.0-5.0 KA units/100 ml