CELL COAT (GLYCOCALYX)

1. Present in Protists and animal cells.
2. Usually made of oligosaccharide side chains of glycolipids and glycoproteins.
3. Cell coat has very charged termini as those of salicylic acid, which attract Ca2+ and Na+ ions.

FUNCTIONS

1. Cell coat protect the PM from mechanical injury.
2. It provides the shape of cell.
3. Functions as filter & regulate passage of solutes.
4. Provides recognition ability to cell, which is related to Ca2+ and Mg2+.
5. ABO antigens are located in terminal carbohydrate of glycocalyx of RBCs.
6. Antigens present in cell coat, recognized by Leucocytes & Macrophages, it is called Histocompatibility.