BIOL 031 Lecture Notes - Lecture 24: University Of Manchester, Endoplasmic Reticulum, Acetylcholine
19 Aug 2020
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Lament along with them: myosin released adp: at the end, myosin releases adp; this causes the head to be tightly bound to actin in the rigor state; repeat. Ca2+ binds to troponin, allowing actin-myosin binding. Actin lament slides toward center of sarcomere. Sarcoplasmic ca2+ atpase pumps ca2+ back into sr. Decrease in free cytosolic (ca2+) causes ca2+ to unbind from troponin. When myosin heads release, elastic elements pull laments back to their relaxed position. Twitch: a single contraction-relaxation cycle in a skeletal muscle ber. Latent period: the short delay between the muscle action potential and the beginning of muscle tension development. Skeletal muscle contraction requires a steady supply of atp. The amount of atp in a muscle ber at an one time is suf cient for only about 8 twitches. Phosphocreatine: back up energy source; has high-energy phosphate bonds created from creatine and atp when muscles are at rest.
