BIOL 150 Study Guide - Final Guide: Sliding Filament Theory, Globular Protein, T-Tubule
Document Summary
Structure a myofribril, one muscle cell, a bundle of muscle fibers, then muscle. Muscle cell has more than one nuclei and mitochondria. Myofibril the contractile structure, with myosin (thick filaments) and actin (thin filaments). This is the center of the muscle cell. It contains calcium ions that helps the muscle contract. Sarcoplasmic reticulum also known as the modified endoplasmic reticulum. A band defined by the length of the myosin; it overlaps actin. H zone defined by myosin that attaches to the mid-line in the a band (not a structure, just an area); no actin (no overlap) I band defined by actin that attaches to the z disc; no myosin (no overlap). Z disc boundary of sarcomere; where the thin filaments attach. Sarcomere : functional unit of striated muscle with thick and thin filaments (from z disc to z disc). The sliding filament model filaments do not change length, the degree of overlap is what changes the sarcomere is shorter.
