Question

Fill in the Blanks

a) Polysaccarides______. A) are glycans. B)have a fixed length. C) are never branched. D) must be homopolysaccharides.

b) Glycoproteins _______. A)are always intracellular.   B) are a small fraction of the total number of proteins in a human cell.   C)contain unbranched oligosaccharides.  D)have oligosaccharides covalently attached to aspartate residues.

c) Oligosaccharides are _______. A)never attached to hormones. B) never found in mucins. C)classified as N- or O-linked when found in gangliosides. D) found in bacterial lipopolysaccharides.

d) Lectins are found _______. A) only in eukaryotes. B) on the surface of hepatocytes. C)only in blood. D) only on the surface of cells.

Answer 1

a. Glycan because is carbohydrate portion of glycoconjugate

b. Glycoprotein are protein which contain oligosaccharide chain. They are present in large fraction. Hence they are always intracellular

c.Oligosaccharides are carbohydrates which are made of 3-10 monosaccharide repeating units. They are binded to lipids or proteins and form glycolipids and glycoproteins by O-glycosidic or N-glycosidic linking units. They are found in bacterial lipopolysaccharides mainly in the cell wall lipopolysaccharides of Gram negative bacteria. . So, the correct option is Found in bacterial lipopolysaccharides.

d. Lectins are carbohydrate sugar binding proteins, mainly the sugar moiety of glycoconjugates which results in precipitation of these glycoconjugates and cell agglutination. Lectins are found in animals, plants, and microorganisms. Lectins are only present on the surface of hepatocytes.

Therfore, the correct answer is option (B).