Skeletal Muscle - have lots of glycogen and myoglobin ....

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Skeletal Muscle Muscle Fibers Skeletal muscle is voluntary and striated . An individual skeletal muscle cell is called a myofiber . These cells are long and thin with multiple flattened nuclei pushed against the outer edge of the cell. These cells are multinucleated because several myoblasts fuse during development to give rise to mature myocytes . The plasma membrane of a myofiber has transverse (T) tubules that penetrate into the interior of the cell. These T-tubules enable electrical stimulation to travel deep into the interior of the cell and activate calcium channels on the sarcoplasmic reticulum . Intracellularly, myofibers have myofibrils organized in parallel within the cell. These myofibrils are composed of special proteins in an arrangement known as a myofilament . These cells also
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Unformatted text preview: have lots of glycogen and myoglobin . Glycogen provides a readily available source of glucose for energy production and myoglobin provides additional oxygen for aerobic respiration. Myofilaments Myofilaments are composed of four major proteins: myosin, actin, troponin and tropomyosin. Myosin and actin are contractile proteins while tropomyosin and troponin are regulatory proteins. These proteins are arranged as shown within the sarcomeres of the myofilaments. Thick Filaments Myosin forms the thick filaments of myofilaments. Myosin proteins are arranged in a bundle with the "heads " directed outward in a spiral array around the bundled "tails". The central area of the thick filament is bare because it consists only of myosin tails....
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This note was uploaded on 01/30/2012 for the course BSC BSC1085 taught by Professor Sharonsimpson during the Fall '10 term at Broward College.

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