Quick Biochemistry - Enzymes (Section 1)

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