The composition of a cell membrane is not uniform for all types of cells. some cell membranes are more rigid than others. rigidity is determined by a variety of factors, one of which is the structure of the carbon chains in the phospholipids that comprise the membrane. two examples of phospholipids are shown below, with one having c―c double bonds in its carbon chains. which phospholipid would be present in the more rigid cell membrane?

The cell membrane is a biological membrane that separates the interior of all cells from the outside environment. It consists of a lipid bilayer with embedded proteins. The basic function of the cell membrane is to protect the cell from its surroundings. The cell membrane controls the movement of substances in and out of cells and organelles. In this way, it is selectively permeable to ions and organic molecules. In addition, cell membranes are involved in a variety of cellular processes such as cell adhesion, ion conductivity and cell signalling and serve as the attachment surface for several extracellular structures, including the cell wall, the carbohydrate layer called the glycocalyx, and the intracellular network of protein fibers called the cytoskeleton. In the field of synthetic biology, cell membranes can be artificially reassembled.