Question

I have just an intuition that the carbohydrate part ofglycoproteins help them to fulfil those tasks like in plasmamembranes. You can also get many more receptors if you can usecarbohydrates too.

For instance, glycoproteins are necessary in recognising whiteblood cells. Antibodies are examples of glycoproteins. So they playa crucial role in our innate and adaptive immunity: MHC interactionwith T cells in adaptive immunity. Other examples: necessary inplatelet aggregation and adherence, components of zona pellucidaand connective tissue. Some hormones are also glycoproteins sonecessary in humoral adaptive immunity: FSH, LH, TSH and EPO.

But why glycoproteins are "better" than proteins withoutcarbohydrates moiety in fulfilling biological tasks?

I still see that both are important, but why the one is betterthan the other one.

In other words: Are there any biological tasks that onlynon-glycoproteins can fulfil, not glycoproteins? Arenon-glycoproteins necessary in some essential biological tasks?

I think the answer to the last two questions is "yes", so whywould one say that glycoproteins are better in fulfillingbiological tasks than non-glycoproteins.