GLYCOSAMINOGLYCANS, PROTEOGLYCANS, AND GLYCOPROTEINS

Question 1

long chains of sugar molecules that are found in the extracellular matrix (ECM) of all tissues throughout the body.

Answer 1

Glycosaminoglycans (GAGs)

Question 2

Found in: cartilage, bone, skin, tendons, ligaments, blood vessels, synovial fluid, vitreous humor of the eye

Answer 2

GLYCOSAMINOGLYCANS

Question 3

natural anticoagulant that helps to prevent blood clot

Answer 3

GAG heparin

Question 4

are long, unbranched, heteropolysaccharide chains composed of a repeating disaccharide unit [acidic sugar–amino sugar]n

Answer 4

GAGs

Question 5

[Acidic sugar can be either D-glucuronic acid or its C-5 epimer L-iduronic acid, and the amino sugar can be either ___

Answer 5

glucosamine or galactosamine.]

Question 6

are strongly negative charged, due to the presence of carboxyl groups that the acidic sugars contain, and sulfate groups.

Answer 6

GAGs

Question 7

6 TYPES GLYCOSAMINOGLYCANS
:

Answer 7

Hyaluronic acid (HA)
Chondroitin sulfate (CS)
Dermatan sulfate (DS)
Heparan sulfate (HS)
Heparin
Keratan sulfate (KS)

Question 8

the only GAG that is not sulfated. It is composed of repeating disaccharide units of N-acetylglucosamine and D-glucuronic acid.

found in all tissues throughout the body, but it is particularly abundant in the synovial fluid of joints and the vitreous humor of the eye.

Answer 8

Hyaluronic acid (HA)

Question 9

composed of repeating disaccharide units of Nacetylglucosamine and D-glucuronic acid or L-iduronic acid. (in cartilage, bone, skin, and other tissues throughout the body)

Answer 9

Chondroitin sulfate (CS)

Question 10

is a type of CS that is distinguished by its high degree of sulfation. (found in skin, tendons, and other tissues.)

Answer 10

Dermatan sulfate (DS)

Question 11

composed of repeating disaccharide units of Nsulfoglucosamine and D-glucuronic acid or L-iduronic acid. (found in the cell membrane and extracellular matrix of all tissues throughout the body.)

Answer 11

Heparan sulfate (HS

Question 12

is a type of HS that is highly sulfated. (found in mast cells and basophils, and it plays a role in blood coagulation.)

Answer 12

Heparin

Question 13

composed of repeating disaccharide units of galactose and N-acetylglucosamine. (found in the cornea, cartilage, and other tissues.)

Answer 13

Keratan sulfate (KS)

Question 14

are the activated forms of the monosaccharides that can be used to elongate the carbohydrate chains

Answer 14

N-acetylglucosamine (GlcNAc)
N-acetylgalactosamine (GalNAc)

Question 15

is synthesized from N-acetylmannosamine and phosphoenolpyruvate.

Answer 15

N-acetylneuraminic acid (NANA)

Question 16

is the only nucleotide sugar in human metabolism in which the carrier nucleotide is a monophosphate.

Answer 16

NANA

Question 17

: can be obtained from the a.) lysosomal degradation of GAGs, or from b.) glucose 6- phosphate via the uronic acid pathway.

Answer 17

Glucuronic acid

Question 18

The end product of glucuronic acid metabolism in humans

Answer 18

D-xylulose 5- phosphate.

Question 19

The source of the sulfate is _____. The sulfation reaction is catalyzed by sulfotransferases.

Answer 19

3’- phosphoadenosyl-5’-phosphosulfate (PAPS)

Question 20

defect in the sulfation of the growing glycosaminoglycan chains where the proper development and maintenance

Answer 20

Chondrodystrophies

Question 21

is a rare lysosomal storage disease in which all sulfatases are nonfunctional due to a defect in the formation of formylglycine, an amino acid derivative required at the active site for enzymic activity to occur

Answer 21

Multiple sulfatase deficiency

Question 22

hereditary diseases caused by a deficiency of any one of the lysosomal hydrolases normally involved in the degradation of heparan sulfate and/or dermatan sulfate.

Answer 22

MUCOPOLYSACCHARIDOSES

Question 23

α-L-iduronidase deficiency

most severe form of MPS

corneal clouding, developmental disability, dwarfing, coarse (dysmorphic) facial features, upper airway obstruction, hearing loss

degradation of dermatan sulfate and heparan sulfate affected

Answer 23

a.) Hurler Syndrome (MPS I H)

Question 24

severe nervous system disorders; developmental disability

Answer 24

b.) San Filippo Syndrome Types A-D (MPS III)

Question 25

Iduronate-sulfatase deficiency
no corneal clouding, but physical deformity and developmental disability are mild to severe
degradation of dermatan sulfate and heparan sulfate affected

Answer 25

c.) Hunter Syndrome (MPS II)

Question 26

β-glucuronidase deficiency
hepatosplenomegaly, skeletal deformity, short stature, corneal clouding, developmental stability
degradation of dermatan sulfate and heparan sulfate affected

Answer 26

d.) Sly Syndrome (MPS VII)

Question 27

are large molecules that are made up of a protein core and one or more GAG chains.
found in the extracellular matrix (ECM) of all tissues throughout the body.

Answer 27

PROTEOGLYCANS

Question 28

are structured like a “bottle brush,” with the protein core at the center and the GAG chains extending out like bristles.

Answer 28

PROTEOGLYCANS

Question 29

An ____ is formed between the xylose and the hydroxyl group of the serine.

Answer 29

O-glycosidic bond

Question 30

are proteins with short chains of sugars (oligosaccharides) attached to them.
found all over the body, including on the surface of cells, in the blood, and in the extracellular matrix.
They differ from proteoglycans in that proteoglycans have very long chains of repeating sugars (GAGs).
Examples: hormones, enzymes, blood group antigens, mucin, collagen, elastin

Answer 30

GLYCOPROTEINS

Question 31

are short chains of sugars that are attached to proteins to form glycoproteins.

Answer 31

Oligosaccharides

Question 32

simple, with only a few sugar residues, or they can be quite complex, with many sugar residues and branching patterns.

For example, the ABO blood group antigens on the surface of red blood cells are determined by the structure of O-linked oligosaccharides.

Answer 32

O-linked oligosaccharides

Question 33

more complex than O-linked oligosaccharides. They all contain a core pentasaccharide, which is a chain of five sugar residues.

Answer 33

N-linked oligosaccharides

Question 34

the sugar chain is attached to the nitrogen atom of an asparagine amino acid

Answer 34

N-linked glycosylation

Question 35

the sugar chain is attached to the oxygen atom of a serine or threonine amino acid residue.

Answer 35

O-linked glycosylation:

Question 36

similar to that of the GAGs
if any one degradative enzyme is missing, degradation by the other exoenzymes cannot continue.

Answer 36

LYSOSOMAL DEGRADATION OF GLYCOPROTEINS

Question 37

caused by a deficiency of any one of the degradative enzymes results in accumulation of partially degraded structures in the lysosomes

Answer 37

Oligosaccharidoses