The cellular membrane, in the case of cells that don't have a rigid cellular wall, outlines the cell and contains the cytoplasm but it's the cytoskeleton that is more responsible for the shape of a cell, which come in a variety of shapes: squamous, cuboide, colunar, neurons, etc. In cells that do have a rigid cellular wall, such as plant cells, it's the cellular wall that gives it <span>its shape.</span>
Proteins serve as antibodies.
