Answer
Complex barrier to the flow of substances out of the cells,and restrictions to inflow of unwanted substances into the cells. The hydrophobic and hydrophilic nature of the cell membrane controls the entry of substances from the extracellular medium into the intracellualr. In addition the polarity restricts certain substance movement across the walls.
Serve as the selective channels for the influx of certain substances into the cells, and the out flux of wastes.This is through ion channels for the movements of ions across.
Provide insulation to the cells,to maintain the constant internal temperature,this is through the presence of lipids as( Phospholipids and cholesterol).The latter prevent the clogging of the lipids in the cell membrane therefore preventing frozen up of the cell membrane,providing insulation.
Separation of metabolic process in the cell.
Explanation:
Cell membrane-This is present in all cells.But the variation of its constituents makes it unique to each cell. Although it performs the same role, the location and role the cells it bounded, reflects its constituents, it is made up of lipids, carbohydrate, protein and cholesterol
Global warming is the answer
Ost proteins that function in the cytosol (such as actin) or in the nucleus (such as DNA polymerase) are synthesized by free ribosomes. Proteins that function within the endomembrane system (such as lysosomal enzymes) or those that are destined for secretion from the cell (such as insulin) are synthesized by bound ribosomes.
<span>As a protein destined for the endomembrane system is being synthesized by a ribosome, the first amino acids in the growing polypeptide chain act as a signal sequence. That signal sequence ensures that the ribosome binds to the outer membrane of the ER and that the protein enters the ER lumen.</span>
