Quick Biochemistry - Enzymes (Section 1)

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