<prompt> The approximate composition of proteins in cell membrane is75552513  <response>: The cell membrane also called the plasma membrane envelops the cell and is a thin, pliable, elastic structure only 7.5 to 10 nanometers thick. It is composed almost entirely of proteins and lipids. The approximate composition is proteins, 55 percent; phospholipids, 25 percent; cholesterol, 13 percent; other lipids, 4 percent; and carbohydrates, 3 percent.Ref: Guyton; 13th edition; Chapter 2 The Cell and Its Functions 