During muscle growth new sarcomeres are added to the end of the myofibril

During muscle growth new sarcomeres are added to the

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During muscle growth, new sarcomeres are added to the end of the myofibril 10.Titin: giant, highly elastic protein that extends from the M line to the Z lines in both directions a. 3 functions of titin i. Serves as scaffolding: helps stabilize the position of the thick filaments in relation to the thin filaments ii. Acts as an elastic spring: helps a muscle stretched by an external force passively recoil when the stretching force is removed 1. This makes titin a parallel-elastic component of the muscle 2
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iii. Participates in signal transduction: it is involved in diverse signaling pathways (such as the pathway for muscle enlargement in response to weight lifting) vii. Cross bridges: extend from the thick filament toward the surrounding thin filaments in the areas where the thick and think filaments overlap 1. They project from each thick filament in all 6 directions towards all 6 surrounding think filaments d. Myosin forms the thick filaments i. Myosin: protein consisting of two identical subunits (each shaped like a golf club) 1. The protein’s tails are intertwines while the heads project out at one end ii. The heads of myosin form the cross bridges between the thick and thin filaments 1. Each cross bridge has two important sites: a. An actin binding site b. A myosin ATPase site 3
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