Essential Biochemistry - Enzymes (Section 2)

  • 1
    How does an enzyme affect the energy profile of a reaction?
    Vastaus
    (A)
    It lowers the activation energy.
  • 2
    Which of the following non-proteins can act in an enzyme?
    Vastaus
    (B)
    RNA
  • 3
    The active site of an enzyme is the region that:
    Vastaus
    (A)
    Binds to the substrate.
  • 4
    Which enzyme is useful in the treatment of gastric ulcers?
    Vastaus
    (C)
    Renin
  • 5
    Enzymes are biological catalysts that:
    Vastaus
    (A)
    Increase the rate of reactions
  • 6
    What is the function of a kinase?
    Vastaus
    (A)
    Transferring a phosphate group
  • 7
    Which factors influence enzyme activity?
    Vastaus
    A
    B
    C
    D
  • 8
    Which of the following is an example of a non-protein component that is essential for enzyme function?
    Vastaus
    (C)
    A cofactor
  • 9
    The substrate concentration at which an enzyme inhibitor has half the maximum velocity is known as:
    Vastaus
    (C)
    Km
  • 10
    In which type of inhibition does the inhibitor bind only to the enzyme-substrate complex?
    Vastaus
    (C)
    Uncompetitive inhibition
  • 11
    What type of inhibitor can be overcome by increasing the substrate concentration?
    Vastaus
    (C)
    Competitive inhibitor
  • 12
    What is the effect of a competitive inhibitor on the Vmax of an enzyme-catalyzed reaction?
    Vastaus
    (C)
    Vmax remains unchanged.
  • 13
    Which class of inhibitors involves the formation of a covalent bond with the enzyme, leading to irreversible inactivation?
    Vastaus
    (D)
    Irreversible
  • 14
    Which enzyme is specifically used in the diagnosis of myocardial infarction?
    Vastaus
    (B)
    CK-MB
  • 15
    Which of the following types of enzyme inhibitors usually bind to the enzyme through covalent bonds?
    Vastaus
    (C)
    Irreversible inhibitors
  • 16
    What is the primary clinical use of measuring AST?
    Vastaus
    (B)
    Diagnosis of liver disease
  • 17
    What happens to the activation energy when an enzyme is present?
    Vastaus
    (B)
    It decreases.
  • 18
    Which of the following is/are classified as a transferase?
    Vastaus
    (D)
    All of the above
  • 19
    Which of the following is a competitive inhibitor?
    Vastaus
    (B)
    Ethanol
  • 20
    Which type of inhibitor can be overcome by increasing substrate concentration?
    Vastaus
    (B)
    Competitive Inhibitor
  • 21
    How does product concentration affect the rate of an enzyme-catalyzed reaction?
    Vastaus
    (D)
    High concentrations can inhibit the reaction.
  • 22
    What is the value that defines the substrate concentration when the reaction rate is half of its maximum value?
    Vastaus
    (B)
    Km
  • 23
    Which enzyme is elevated in liver diseases?
    Vastaus
    (C)
    Alanine transaminase
  • 24
    Which of the following is the most appropriate description of Km (Michaelis constant)?
    Vastaus
    (C)
    The substrate concentration at which the reaction rate is half its maximum.
  • 25
    Which of the following factors can affect the rate of an enzyme-catalyzed reaction?
    Vastaus
    A
    B
    C
    D
  • 26
    Which of the following enzymes is inhibited by disulfiram, leading to the buildup of acetaldehyde?
    Vastaus
    (B)
    Aldehyde dehydrogenase
  • 27
    The Lineweaver-Burk plot is used to:
    Vastaus
    (B)
    Calculate the Km and Vmax values.
  • 28
    Which of the following describes the function of the enzyme amylase?
    Vastaus
    (C)
    Breaks down carbohydrates
  • 29
    Which of the following can act as enzyme inhibitors?
    Vastaus
    (D)
    All of the above.
  • 30
    Which of the following are examples of enzymes useful in clinical diagnostics?
    Vastaus
    A
    B
    C
  • 31
    What is the main therapeutic use of asparaginase?
    Vastaus
    (C)
    Treating certain types of leukemia.
  • 32
    What effect does a noncompetitive inhibitor have on Vmax and Km?
    Vastaus
    (A)
    Vmax decreases, Km stays the same
  • 33
    In competitive inhibition, the inhibitor usually resembles:
    Vastaus
    (A)
    The substrate.
  • 34
    What is the role of an activator in enzyme kinetics?
    Vastaus
    (C)
    It enhances the activity of the enzyme.
  • 35
    Which of the following enzyme markers are typically evaluated during the diagnosis of myocardial infarction (MI)?
    Vastaus
    A
    B
    C
  • 36
    In a Lineweaver-Burk plot, what does the x-intercept represent?
    Vastaus
    (B)
    -1/Km
  • 37
    Which of the following is a characteristic of the transition state?
    Vastaus
    (A)
    It is the highest energy state during the reaction.
  • 38
    Which of the following enzymes is a tetrameric enzyme?
    Vastaus
    (A)
    Lactate dehydrogenase (LDH)
  • 39
    The digestive enzymes belong to:
    Vastaus
    (C)
    Hydrolases
  • 40
    How do enzymes affect the equilibrium of a reaction?
    Vastaus
    (C)
    They do not affect the equilibrium.
  • 41
    Which type of inhibitor increases the Km, but does not change the Vmax?
    Vastaus
    (A)
    Competitive inhibitor
  • 42
    Enzymes are classified into different groups based on:
    Vastaus
    (B)
    The type of reaction they catalyze.
  • 43
    Which of the following is a characteristic of creatine kinase (CK) isoenzymes?
    Vastaus
    A
    B
    C
  • 44
    What is the primary function of the enzyme, Lactate Dehydrogenase (LDH)?
    Vastaus
    (A)
    Catalyzes the oxidation of L-lactate to pyruvate
  • 45
    What is the mechanism of action of aspirin?
    Vastaus
    (A)
    Irreversible inhibitor of cyclooxygenase (COX)
  • 46
    Which enzyme is primarily involved in the metabolism of ethanol?
    Vastaus
    (B)
    Alcohol dehydrogenase
  • 47
    At high substrate concentrations, the reaction rate:
    Vastaus
    (C)
    Reaches a maximum.
  • 48
    Which of the following is a key feature of allosteric enzymes?
    Vastaus
    B
    C
  • 49
    Which of the following is a characteristic of irreversible inhibitors?
    Vastaus
    (B)
    They often form covalent bonds with the enzyme.
  • 50
    Which type of inhibition alters the Vmax but not Km?
    Vastaus
    (B)
    Noncompetitive inhibition