Muscle contraction

• Steps on muscle contraction

  Action potential reach muscle, stimulating a response

  Calcium ions binds to troponin causing tropomyosin to move from binding site

  ADP attaches to myosin head to act as a cross bridge

  Actin slides over myosin

  ADP and Pi is released

  ATP attached to head of myosin causing it to change shape and detach from Actin

  APTase cause ATP to be hydrolysed into ADP.

  Energy is released

  Process is repeated
• How does rigor mortise make the muscles stiff

  Rigor occurs due to decrease in ATP production. Without APT myosin cannot detach from Actin therefore preventing the muscles from relaxing

  Too much calcium ions make the muscles stiff.