Quick Biochemistry - Enzymes (Section 1)

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