BIOL273 Lecture Notes - Dragon Boat, Kinesin, Myofibril
27 May 2013
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Muscle contraction occurs when filaments slide tgt (pg. Degree of overlap b/t thick and thin filaments increases. Band width and zones changes: distance from z-disk to z-disk becomes smaller, closer tgt when contraction occurs. Each sarcomere gets shorter > each myofibril in muscle cell gets shorter as well > entire muscle shortens. Increase in internal tension (i. e. the force that tends to pull the ends of the muscle toward each other) the overall muscle length may decrease (depending on the size of its load). Increase in internal tension when contraction occurs, but not necessarily the decrease in length of the overall muscle. The myosin heads attach to spots of the thin filament and pull the thin filament forward repeatedly. Requires energy = atp (myosin use atp to force the sliding tgt of the filaments) Myosin: a motor protein (kinesin in nervous system)
