Final answer:
The glycocalyx, often described as a 'cell coat,' is made up of glycoproteins, glycolipids, and extended carbohydrates that are integral to cell-to-cell recognition and immunity. It is crucial for cells' identity and interaction with their environment, and its composition is crucial in transplantation and immune responses.
Step-by-step explanation:
The glycocalyx, often referred to as a "cell coat," is a viscous, gel-like covering that surrounds the plasma membranes of cells, particularly in eukaryotes. This coat is composed of glycoproteins, glycolipids, and carbohydrates that extend from these macromolecules into the extracellular space. The glycocalyx plays critical roles in cell-to-cell recognition and communication, functioning in cell identification, immunity through self/non-self determination, and embryonic development. It also assists in the formation of tissues and facilitates the interaction of cells with their watery environment, helping in the uptake of substances dissolved in the water. The specific composition of the glycocalyx is genetically determined, giving cells their unique identity and allowing the immune system to distinguish between self and non-self entities, which is crucial for the proper functioning of the body's defense mechanisms. Additionally, it is involved in pathophysiological processes, like the rejection of transplanted organs because the recipient's immune system can recognize the foreign glycocalyx as non-self.