Final answer:
Oligosaccharides on glycosylated proteins play a major role in cell recognition and cell adhesion, but they do not increase plasma stability.
Step-by-step explanation:
The main role for oligosaccharides on glycosylated proteins is cell recognition and cell adhesion. Oligosaccharides attached to proteins help identify and differentiate cells, such as the blood type A, B, AB, or O, which are defined by the linked oligosaccharides on red-blood cells.
They play a major role in membrane protein function and are part of the glycocalyx, along with glycoproteins and glycolipids, contributing to cell-to-cell recognition. However, the main role that oligosaccharides do NOT play on glycosylated proteins is to increase plasma stability.