*
* Acetylcholine
* Actin
* ATP
* Ca+ ions
* Myosin heads
* Na+/K+ ions
* Troponin
* Tropomyosin
* Sarcoplasmic reticulum
* Z-line
*
*Binds to sarcolemma
*Opens Na+/K+ gated ion channels
*
*Pulled by myosin
*Attaches to Z-line
*
*Energizes the power stroke of
myosin head
*Disconnects the myosin cross
bridge from the binding site on
actin.
*Fuels the pump that actively
transports calcium ions back into
the sarcoplasmic reticulum.
*
*Bind to troponin
*Help expose binding sites on
actin
*
*Powered by ATP, pull actin
filaments closer together
*
*Depolarize muscle cell
*Cause Ca+ ions to leave
sarcoplasmic reticulum
*
*Binds to tropomyosin
*When Ca+ present, helps slide
tropomyosin off binding sites
*
*Covers binding sites on actin
where myosin heads bind
*
*Storage of Ca+ ions
*Released during depolarization
*
*Pulled together during
contraction
*Attached to actin myofilaments
*
*Click here to see a quick animation
review…
*
* Acetylcholine
* Actin
* ATP
* Ca+ ions
* Myosin heads
*
* Na + /K + ions
* Troponin
* Tropomyosin
* Sarcoplasmic reticulum
* Z-line