EXSS1029 Lecture Notes - Lecture 2: Myosin Head, Muscle Hypertrophy, Muscle Atrophy

• School: University of Sydney
• Department: Exercise and Sport Science
• Course: EXSS1029
• Professor: Dr Tom Gwinn

Document Summary

Large protein molecule of 2000 amino acids. Source of active force production in muscle. Body formed by a tail section called the myosin heavy chain (mhc) Head (crossbridge) is a globular shape made of the motor domain and lever arm. Myosin molecule = 2 mhcs + 4 mlcs. Myosin molecule = 2 mhcs binded together (double headed molecule) Protein forming the body of myosin = myosin heavy chain. Head = sub components motor domain and a lever arm. Lever arm - (each wrapped with 2 mlcs) (cid:373)ust (cid:271)e stre(cid:374)gthe(cid:374)ed so it does(cid:374)(cid:859)t (cid:271)e(cid:374)d fro(cid:373) for(cid:272)es of atta(cid:272)h(cid:373)e(cid:374)ts to (cid:373)otor do(cid:373)ai(cid:374)/tail. Myosin light chain 1 and myosin light chain 2 wrap around lever arm to strengthen it (head) Enzyme catalytic site that binds atp or adp + pi. Converts small movements of the motor domain into large movements of the lever arm. Head = end of mhc and 2 mlc around lever arm.