where are actin filaments located in the cell
Actin An actin protein is the monomeric subunit of two types of filaments in cells: microfilaments, one of the three major components of the cytoskeleton, and thin filaments, part of the contractile apparatus in muscle cells. It can be present as either a free monomer called G-actin (globular) or as part of a linear polymer microfilament called F-actin (filamentous), both of which are essential for such important cellular functions as the mobility and contraction of cells during cell division.
Sarcolemma The sarcolemma (sarco (from sarx) from Greek; flesh, and lemma from Greek; sheath.) also called the myolemma, is the cell membrane of a striated muscle fiber cell.[1] It consists of a plasma membrane, which is a lipid bilayer, and an outer coat consisting of a thin layer of polysaccharide material (glycocalyx) that contacts the basement membrane, which contains numerous thin collagen fibrils and specialized proteins such as laminin[2] that provide a scaffold for the muscle fiber to adhere to. Through transmembrane proteins residing in the plasma membrane, the actin skeleton inside the cell is connected to the basement membrane and the cell's exterior. At each end of the muscle fiber, the surface layer of the sarcolemma fuses with a tendon fiber, and the tendon fibers in turn collect into bundles to form the muscle tendons that then adhere onto bones.