Answer:
The cell membranes consist of a lipid bilayer (a double layer of lipids) in which various proteins are immersed, these act as pores through which certain substances can enter or leave the cell. The carbohydrate content of the plasma membrane varies between 2 and 10% of its weight, they support the cell membrane by adhering to it
Step-by-step explanation:
The lipid bilayer has been established as the universal basis for the structure of the cell membrane. Membrane proteins have both structural and enzymatic functions; ferritin is a protein that transports and, at the same time, stores iron; myosin is involved in muscle contraction, but it also functions as an enzyme capable of hydrolyzing ATP, and so many more examples could be given.In living beings, transport phenomena are essential, either to carry a hydrophobic molecule through a aqueous medium (transport of oxygen or lipids through the blood) or to transport polar molecules through hydrophobic barriers (transport through the plasma membrane). Biological transporters are always proteins. The carbohydrate part (biomolecules composed of carbon, hydrogen and oxygen, whose function is to provide immediate and structural energy) of the molecule is always on the outside of the cell. Some proteins form water-filled channels through which polar or electrically charged substances can pass that do not pass through the phospholipid layer.