Final answer:
Carbohydrate chains of glycoproteins, proteoglycans, and glycolipids are located on the external side of the cell membrane, forming part of the glycocalyx that is vital for cell recognition and immune response.
Step-by-step explanation:
On what side of the membrane are the carbohydrate chains of glycoproteins, proteoglycans, and glycolipids located? The carbohydrate chains of glycoproteins, proteoglycans, and glycolipids are located on the external (noncytosolic) side of the membrane. These carbohydrates form a glycocalyx, which is found on the exterior surface of cells and is essential for cell recognition and immune response. The glycocalyx includes carbohydrate chains bound to proteins (glycoproteins) or lipids (glycolipids) that can be straight or branched and consist of 2-60 monosaccharide units. This sugar coating is hydrophilic, attracting water and facilitating cell interaction with substances dissolved in the water, aiding cell recognition and serving as a barrier against pathogens.