Question

What are three specific functions of the cell membrane? Cell membranes are a mosaic of lipid and protein molecules. Assign the functions you listed to either protein or lipid.

Answer 1

answer:

cell membrane functions: cell membrane also called as plasma membrane.

a).They keep toxic substances out of the cell.

b).They contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment.

c). They separate vital but incompatible metabolic processes conducted within organelles.

Membranes made up of largely of a lipid bilayer, which is a double layer of phospholipid, cholesterol, and glycolipid molecules that contains chains of fatty acids and determines a membrane is formed into long flat sheets or round vesicles.Embedded in the lipid bilayer are large proteins, many of which transport ions and water-soluble molecules across the membrane.Few proteins in the plasma membrane form open pores, called membrane channels,they allow the free diffusion of ions into and out side of the cell. Some others bind to specific molecules on one side of a membrane and transport the molecules to the other side. Sometimes one protein simultaneously transports two types of molecules in opposite directions. Most plasma membranes are about fifty percent protein by weight,the membranes of some metabolically active organelles are seventy five percent protein.