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Unformatted text preview: Skeletal Muscle Ÿ Attached to bones and responsible for their movement Ÿ Skeletal muscle à bundle of long fiber à fiber is a single cell with multiple nuclei à myofibrils Ÿ Myofibrils= muscle + small fibers Ÿ Myofibrils composed of 2 types of my filaments: Thick and Thin Ÿ Thick: myosin molecules Ÿ Thin: 2 strands of actin and 1 strand of regulatory protein Structure of a Sarcomere Ÿ Sarcomere: 1 repeating unit Ÿ Z line: attaches to thin filament Ÿ I band: gap with only thin filament Ÿ A band: length of thick filament Ÿ H zone: only thick filament Sliding of filaments Ÿ Sliding-filament model : As sarcomere shortens, the thick and thin filaments overlap one another Ÿ Sliding due to actin and myosin interaction Myosin head and interaction with actin Ÿ Myosin head powers muscle contractions and binds to ATP to hydrolyze it to ADP + P i that triggers steps for myosin to bind to actin forming cross bridges to pull thin filament toward the center of the sarcomere Ÿ Creatine phosphate and glycogen allows for repetitive contractions Creatine: make ATP quickly by transferring P i to ADP Glycogen: breaks down glucose to generate ATP through glycolysis...
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- Spring '08
- Biology, AP, myosin interaction Myosin, myosin interations Myosin