∙ The cell membrane is made up of lipids and proteins.
∙ The proteins are synthesised by the ribosomes present on the surface of rough endoplasmic reticulum (RER), while the lipids are synthesised by smooth endoplasmic reticulum (SER).
∙ These proteins and lipids obtained from the endoplasmic reticulum help in the building of the cell membrane.
∙ This process is known as membrane biogenesis.