BIOL 201 Lecture Notes - Lecture 14: Godfrey Kneller, Troponin, Nebulin
Document Summary
During development, myoblasts fuse together to form one multinucleated muscle cell. Z disks, thick filaments, thin filaments on sides (refer to phgy209) Thickness of a-band remained constant; i band goes in. On right: huge black dots are thick filaments. One signal --> myosin grabs ~4 times within. Myosin binds atp; atp causes head to release from actin; Atp controls the affinity of the motor protein (myosin) for the filament (actin) This contraction mechanism is happening in all muscle. It is the relaxation of that restrained myosin head that changes chemical energy to mechanical energy, allowing muscle to contract and do work! Protein in meat is just actin and myosin! After animal is killed in meat industry, initially it"s pretty flexible. Once muscle has entered rigor mortis (when cytoplasm runs out of atp), myosin is trapped in the attached state; your myosin is permanently stuck like that and muscle becomes stiff (stuck in strained state!)
