KINS 1223 Lecture Notes - Lecture 4: Myofilament, Myosin, Actin

• School: Temple University
• Department: Kinesiology
• Course: KINS 1223
• Professor: Kyle Harris

Document Summary

A thick filament because made up of many myosin molecules. One myofilament stays stationary and the other myofilament moves. Myosin heads move, but myosin as a whole stays put. Myosin tails do not one molecule multiple myosins put together = this image. Conversion of chemical energy to mechanical energy (mechanical work) Contraction is a sequence of steps/ reactions. Nerve impulse arrives at the muscle fiber. Now called a muscle action potential (ap) Electrocution - electricity causes muscles to contract and can"t let go of the object. Step 2: action potential spreads over the surface of the sarcolemma. Ap travels along t-tubules past terminal cisternae. Trying to get ca out of the system. Step 4: ca catalyzes key opening lock. Tugs on tropomyosin to move it away from the active site. When troponin binds with calcium it changes shape (twists) Myosin cross bridges attracted to the active site. A cross-bridge is when myosin head binds to the active site.