91400 Lecture Notes - Lecture 15: Duchenne Muscular Dystrophy, Myosin Head, Sarcomere
Document Summary
Each molecule resembles two golf clubs twisted together. Myosin heads (cross bridges) extend toward the thin laments. * held in place by the m line proteins. * thin laments are made of actin, troponin and tropomyosin. * myosin-binding site on each actin molecule is covered by tropomyosin in relaxed muscle. * the thin laments are held in place by z lines. From one z line to the next is a sacromere. * m line (myomesin) connects to titian and adjacent thick laments. An inelastic protein helps align the thin laments. Links thin laments to sacrolemma and transmits the tension generated to the tendon. Gains protein that functions as a molecular spring which is responsible for the passive elasticity of muscle. Links actin in outermost myo laments to transmembrane proteins and eventually to brous endomysium surrounding the entire muscle cell. Transfers forces of muscle contraction to connective tissue around muscle cell.
