Essential Biochemistry - Muscle (Section 2)

  • 1
    Which of the following is NOT an accessory protein of myofilaments?
    Vastaus
    (A)
    Actin
  • 2
    In the 'sliding filament model', the filaments that slide are:
    Vastaus
    (C)
    Both actin and myosin
  • 3
    Which of the following proteins are involved in muscle contraction, except:
    Vastaus
    (C)
    Myoglobin
  • 4
    Which of the following is a source of energy for muscle contraction, primarily used for short bursts of activity?
    Vastaus
    (B)
    Creatine phosphate
  • 5
    Which of the following is a function of myosin?
    Vastaus
    (C)
    Hydrolyzes ATP
  • 6
    The Z-lines is made of the protein:
    Vastaus
    (C)
    Desmin
  • 7
    Which of the following is the most accepted model of muscle contraction?
    Vastaus
    (A)
    Sliding filament model
  • 8
    What specific event directly causes the myosin head to detach from actin?
    Vastaus
    (B)
    ATP binding to myosin
  • 9
    What does ATP do in muscle contraction?
    Vastaus
    (D)
    All of the above
  • 10
    Which of the following happens during the power stroke?
    Vastaus
    (C)
    Myosin head pulls the actin filament
  • 11
    The basic structural unit of a muscle fiber is the:
    Vastaus
    (A)
    Sarcomere
  • 12
    What is the primary function of ATP in muscle contraction?
    Vastaus
    (A)
    To provide energy for the power stroke
  • 13
    What is the role of troponin in muscle contraction?
    Vastaus
    (D)
    All of the above
  • 14
    What is the main function of the sarcoplasmic reticulum (SR) in muscle cells?
    Vastaus
    (B)
    Store and release calcium ions
  • 15
    Which of the following does not change length during muscle contraction?
    Vastaus
    (C)
    A band
  • 16
    The basic contractile unit of striated muscle is the:
    Vastaus
    (C)
    Sarcomere
  • 17
    What is the primary function of the sarcoplasmic reticulum (SR) in muscle cells?
    Vastaus
    (C)
    Calcium storage
  • 18
    The 'power stroke' of muscle contraction is directly driven by:
    Vastaus
    (B)
    The hydrolysis of ATP
  • 19
    Which of the following describes the role of the H zone in a sarcomere?
    Vastaus
    (A)
    Region containing only thick filaments
  • 20
    Which of the following best describes the role of tropomyosin?
    Vastaus
    (B)
    Covers myosin binding sites on actin
  • 21
    Which of the following is the key regulator of muscle contraction?
    Vastaus
    (A)
    Calcium ions
  • 22
    Which molecule directly blocks the binding of myosin to actin?
    Vastaus
    (B)
    Tropomyosin
  • 23
    During muscle contraction, the thick and thin filaments:
    Vastaus
    (C)
    Overlap each other
  • 24
    What is the role of creatine phosphate in muscle contraction?
    Vastaus
    (B)
    Regenerates ATP
  • 25
    The binding of which molecule initiates the cross-bridge cycle?
    Vastaus
    (A)
    ATP
  • 26
    Which muscle type is generally not striated?
    Vastaus
    (C)
    Smooth muscle