KINESIOL 2C03 Study Guide - Final Guide: Reuptake, Tetanus, Endomysium
6 Apr 2017
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Made of actin (thin) and myosin (thick: actin is surrounded by troponin and tropomyosin. 1 actin has 3 myosin, 1:3/ 1 myosin has 6 actin, 1:6. Sarcomere is 2um in length (short 1. 5, long 3. 5) *the longest muscle in the body is the sartorius. Powerstroke: atp binds to cause myosin head to detach from actin (cb, atp splits into adp and pi (hydrolysis), cb springs upright, and energy from hydrolysis reactivates an atp (for step 1, pi is released. Calcium binds to troponin and pulls tropomyosin to expose actin binding sites. Cb binds tightly to actin: atp energy and adp are released. Atp in step 1 allows this powerstroke to continue (step 1 being myosin detaching, and it will reattach to pull again) Sarcolemma = depolarization occurs -> calcium is released -> binds to troponin = cb cycle. 1 muscle action = twitch: this occurs when calcium release is occurring faster than calcium reuptake.
