BIOL 153 Lecture Notes - Lecture 9: Vimentin, Angiotensin, Intermediate Filament
Document Summary
Tni inhibitory subunit that binds to actin during relaxed state of muscle. Tnt helps tropomyosin position itself properly on actin during contraction. Tropomyosin rod-shaped protein which wraps around the actin core of the thin filament to help stiffen it in a relaxed muscle fiber, it blocks the active site of the actin so that a myosin head cannot bind. What is it? during contraction, thick and thin filaments do not change their length, but slide past each other (overlapping further) as a result, individual sarcomeres shorten myofibrils shorten the entire cell shortens. What causes the asliding@ of the filaments? this concept is best understood if we break it down into steps: Muscle fibers are stimulated by the nervous system, causing an ap that propagates along the sarcolemma and down the t-tubules. Ap causes terminal cisternae of sr to release ca++ into the sarcoplasm where it binds with troponin.
