What are the main functions of the cell membrane?

The cell membrane's primary function is protecting the cell. It acts as a physical barrier to the entry of anything into the cell. The cell contents are also enclosed in the cell membrane, thus acting as a medium of protection and a barrier of toxic substances in the cell. The membrane also helps with the transportation of nutrients into the cell and the transportation of toxic substances. The transportation happens because of channels and receptors that give room for specific molecules such as ions and nutrients to pass through. It also does the same for extracellular activities and allows them out of the cell. Some of the extracellular activities include getting rid of toxic substances. The cell membrane also separates metabolic processes that take place in the organelles.