A&P 1 exam 3 (part 2)

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A&P 1 exam 3 (part 2)
2014-11-07 15:41:09
anatomy physiology fall 2014 exam

Mechanism of Muscle Contraction Fall 2014
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  1. basic unit of contraction
  2. what extends from z-line to z-line
  3. involved in turning contraction on and off
    regulatory proteins
  4. what causes sarcomere to contract?
    reaction of actin and myosin
  5. repeated unit of thick and thin that gives you the striations
  6. has actin and regulatory proteins
    thin myofilaments
  7. has myosin
    thick myofilaments
  8. 3 thin filaments?
    • actin monomer
    • actin polymer
    • regulatory proteins
  9. shape of actin monomer?
  10. yellow disk or circle where actin interacts with myosin
    binding sites
  11. actin monomers patched together to form a string
    actin polymer
  12. use 2 of these strings to make thin filaments
    actin polymer
  13. with actin polymers, why is rotation important?
    binding sites can face in all different directions
  14. 2 types of regulatory proteins?
    • tropomyosin
    • troponin
  15. sits on top of binding sites
  16. found along tropomyosin and is a molecule that interacts with calcium ion
  17. what happens if binding sites are blocked?
    sarcomere cannot contract
  18. 2 shapes of troponin and tropomyosin?
    either blocks or exposes binding sites
  19. once binding sites are exposed what happens?
    contraction is automatic
  20. how to control contraction?
    by controlling myosin access to binding sites
  21. parts of myosin monomer?
    • stalk
    • head
    • crossbridge
  22. stalk of myosin?
    linear end
  23. head of myosin monomer?
    globular end
  24. crossbridge of myosin monomer?
    attachment of head to actin
  25. high energy form?
    cocked position of myosin
  26. low energy form
    rotator position of myosin
  27. from high to end, myosin monomer: ___ rotates towards ___
    • head
    • stalk
  28. heads face both directions
    myosin polymer
  29. thick filaments grab thin on both sides and pull in
  30. what happens during the resting state?
    • no myosin-actin building
    • tropomyosin blocking binding sites on actin
    • calcium is stored in sarcoplasmic recticulum
    • all myosin heads are in cocked position
  31. initiation of contraction?
  32. message relaying down?
    action potential
  33. during the resting state there is no?
  34. stimulation is associated with?
    neural impulse
  35. during stimulation what happens?
    neural action potential arrives at muscle fiber
  36. during stimulation, the muscle fiber conducts
    the action potential
  37. during stimulation, the sarcoplasmic recticulum
    releases calcium into the cell, then the calcium binds to tropomin
  38. when exposing binding states you?
    change shapes
  39. what happens when binding sites are exposed?
    binding of calcium to troponin
  40. binding of calcium to troponin cause a conformational change in troponin
    tropomyosin complex
  41. ____ rotates, thereby exposing myosin binding sites on action
  42. myosin in its low energy state creates?
  43. myosin in its high energy state is ?
  44. once binding sites on action are exposed, myosin heads automatically bind to actin
    crossbridge formation
  45. letting go of actin and picking up ATP
    release crossbridges
  46. release 1 phosphate, then back with ADP and actin
    recock myosin head
  47. the myosin head is recocked when
    it lets go of actin and picks up ATP
  48. only way to stop contraction?
    block binding sites
  49. uses active transport to pump calcium back in