KINESIOL 1Y03 Lecture Notes - Lecture 31: Atp Hydrolysis, Serca, Vertebra

• School: McMaster University
• Department: Kinesiology
• Course: KINESIOL 1Y03
• Professor: Krista Howarth

Document Summary

At either side of the transverse tubules we have an enlarged area of the sarcoplasmic reticulum (sr) called the terminal cisterna > forms the triad with the t-tubules. Sr is sensitive to the map"s/changes in membrane potentials and so the sr is signalled to release calcium >>> binds to troponin > tropomyosin moves off the active sites of actin. Rapid process where the myosin head bends toward m-line and detach from actin and re-attach as long as calcium still bound to troponin but closer to the z-disk. All heads binding and releasing at different times. At end of excitation coupling, myosin head has adp and a phosphate attached to it. (used to be. Atp but broke down to adp and inorganic phosphate group). So the head stores energy which comes from the atp hydrolysis when there is myosin atpase. Each head uses atp to create the movement.