GLYCOPROTEINS

Question 1

A protein covalently linked to carbohydrates

Answer 1

glycoprotein

Question 2

What types of glycosidic bonds are found in glycoproteins?

Answer 2

N-glycosidic, O-glycosidic, and glycosylphosphatidylinositol-anchored (glypiation)

Question 3

Function of glycans in glycoproteins?

Answer 3

Cell signaling, recognition, stability, and folding.

Question 4

Process of N-glycosylation?

Answer 4

Attachment of GlcNAc-PI to Asn residues.

Question 4

Process of O-glycosylation?

Answer 4

Attachment of GalNAc to Ser/Thr residues

Question 5

Impaired glycoprotein function due to defective glycosylation.

Answer 5

Congenital Disorders of Glycosylation (CDG)

Question 5

What is glypiation?

Answer 5

Attachment of GPI anchor to C-terminal amino acids.

Question 6

How does altered glycosylation contribute to cancer?

Answer 6

Changes in cell-cell interactions and receptor-ligand binding.

Question 7

Role of glycoproteins in immunodeficiency?

Answer 7

Impaired immune response due to defective glycoprotein function.

Question 8

Enzymes catalyzing glycosidic bond formation

Answer 8

glycosyltransferases

Question 8

Enzymes catalyzing glycosidic bond hydrolysis.

Answer 8

glycosidases

Question 9

Proteins binding specific glycans

Answer 9

lectins

Question 10

What is the role of glycoproteins in protein stability?

Answer 10

Maintaining protein conformation and preventing degradation.

Question 10

What is the role of glycoproteins in immune response?

Answer 10

Activating immune cells and mediating inflammation.

Question 11

What is the role of glycoproteins in cell signaling?

Answer 11

Mediating cell-cell interactions and receptor-ligand binding.

Question 12

enzyme responsible for N-glycosylation?

Answer 12

Oligosaccharyltransferase.

Question 13

Enzymatic attachment of sugars to proteins

Answer 13

glycosylation

Question 14

Nonenzymatic attachment of sugars to proteins

Answer 14

glycation

Question 15

This process can have serious pathologic consequences

Answer 15

glycation

Question 16

Often found in glycoproteins, attached to galactose, N-acetylglucosamine, or N-acetylgalactosamine

Answer 16

Sulfate

Question 17

Can be used to purify glycoproteins

Answer 17

Lectins

Question 17

Plant lectins were formerly called

Answer 17

Phytohemagglutinins

Question 18

Common sugar in N-linked glycoproteins

Answer 18

Mannose

Question 19

Present in both N-and O-linked glycoproteins

Answer 19

N-Acetylgalactosamine

Question 20

An important red cell membrane glycoprotein that contains both O-and N-linked oligosaccharides

Answer 20

Glycophorin

Question 21

Four subclasses of O-glycosidic linkages

Answer 21

N-acetylgalactosamine-Ser(Thr) Proteoglycans Collagen Nuclear and cystolic proteins

Question 22

The predominant linkage that found in mucins

Answer 22

N-acetylgalactosamine-Ser(Thr)

Question 23

Contain a galactose-galactose-xylose trisaccharide attached to serine

Answer 23

Proteoglycans

Question 24

Side chains consisting of single N-acetylglucosamine attached to serine or threonine residue

Answer 24

Nuclear and cystolic proteins

Question 24

Contain galactose-hydroxy-lysine linkage

Answer 24

Collagen

Question 25

Have a high content of O-linked Oligosaccharides

Answer 25

Mucins

Question 26

Oligosaccharide branches are often referred as

Answer 26

Antennae

Question 27

Biosynthesis of N-linked Glycoproteins involves

Answer 27

Dolichol-P-P-Oligosaccharides

Question 28

These ensure correct folding of proteins in the endoplasmic reticulum

Answer 28

Glycoproteins & Calnexin

Question 29

A chaperone protein in the ER membrane

Answer 29

Calnexin

Question 30

Soluble ER protein that performs similar function to that calnexin

Answer 30

Calreticulin

Question 31

3 Functions of GPI

Answer 31

Mobility Signal transduction target proteins

Question 32

The overall series of reactions which involve in the browning of certain foodstuffs during storage or heating

Answer 32

Maillard reaction

Question 32

Important in causing tissue damage in diabetes mellitus

Answer 32

Advanced glycation End-Products (AGEs)