Quick Biochemistry - Enzymes (Section 1)

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