Question

N-linked oligosaccharides:

a. don't contain several mannoses.

b. don't contain N-acetylglucosamine.

c. constitute the bigger part of glycoproteins.

d. can't bind additional sugars to the mannose part of the pentasaccharide core.

e.can't bind sialic acid to the pentasaccharide core.

What is the minimal number of negatively charged carboxylate or sulfate groups in one unit of glycosaminoglycan?

a. 5

b. 1

c. 3

d. 4

e. 2

Answer 1

1. Option C is correct

Reason-

Oligosaccharide chains of glycoproteins are chemical markers used to tag proteins by attaching to it at either of N- or O-glycosidic bonds. O-linked oligosaccharides are short as they have only one to four sugar residues while on the other hand N-linked oligosaccharides exist in wide varieties.

N-linked oligosaccharides consists of a pentasaccharide core that has three mannose and two N-acetylglucosamine residues. Along with additional sugars can be attached to the core to form large variety of oligosaccharide.

Hence, option C is correct

2. Option B, 1

Out of the two sugars in the repeating unit of glycosaminoglycan has a negatively charged carboxylate or sulfate group. Thus, option B is correct