BIOL 121 Lecture Notes - Lecture 13: Cell Membrane, Endoplasmic Reticulum, Myofilament
Document Summary
A whole muscle is made up of fascicles. Fascicles are made up of bundles of muscle cells (also referred to as muscle fibers) Within each muscle cell are long cylindrical structures called myofibrils. Myofibrils are made up of myofilaments which contain the actual proteins responsible for contraction. Myofilaments can either be think or thing (actin or myosin) Skeletal muscle is striated: cause by the arrangement of thin and hick myofilaments. Sarcolemma: cell membrane of a muscle cell. Sarcoplasm: like cytoplasm, within the cell. Mitochondria: contain many, responsible for atp production. Myofibrils are made up of a number of proteins - some are responsible for contraction whereas some are responsible for structure. Globular protein which is linked to other g-actin molecules & forms a two-stranded alpha-helical chain. Each g-actin contains a myosin binding site. Rod shaped protein composed of two protein chains wrapped together.
