BIO 208 Lecture Notes - Lecture 9: Myoglobin, Anaerobic Respiration, Phosphocreatine
1 Nov 2016
School
Department
Course
Professor
Document Summary
Major players of muscle contractions: thick filaments (myosin filaments, thin filaments. Myosin: one myosin filament is composed of approximately 500 myosin filaments, each myosin molecule consists of a pair of myosin subunits twisted around each other. Long twisted double helix of globular proteins. Each bed has an active site that can bind. Long filamentous protein that is twisted around the f-actin. Function: to prevent myosin from binding when not initiated by nervous system by inhibition. When at rest active sites are covered: troponin complex. Function: to remove tropomyosin from f-actin active site so myosin can bind: the thin filament is 1mm long. Other end parallel to other actin filaments and the myosin filament. Calcium ions: released by sr in response to depolarization, floods in cytosol, binds with troponin c, causes a conformational change in troponin complex which pulls the tropomyosin off the f-actin active sites allowing myosin heads to bind. Depolarization stimulates sr to release ca+: 3.
