What role do sugar-coated proteins play in cell?

Question

The external faces of some of the proteins in the plasma membrane have carbohydrate groups attached to them. What are they called and what role do such "sugar-coated" proteins play in the life of the cell?

Answer 1

These are called Glycoproteins.

Depending on the functional group and the protein they have various functions but generally are important in cell-cell interactions.

These are especially important to white-blood cells and the immune system, allows the system to recognize cells.