glycolipids and glycoproteins

Question 1

mannose-6-P is synthesized from-

Answer 1

fructose-6-P using phosphomutase isomerase

Question 2

amino sugars are all derived from-

Answer 2

glucosamine-6-P

Question 3

glucosamine-6-P is derived from-

Answer 3

fructose-6-P using aminotransferase

Question 4

N-acetylglucosamine-6-P is derived from-

Answer 4

fructose-6-p –> glucosamine-6-P using N-acetyltransferase

Question 5

2 main components of GAGs

Answer 5

• uronic acid (glucuronic or iduronic)

- N-acetlated hexosmaine (often sulfated)

Question 6

what provides the sulfates for sulfating of proteoglycans?

Answer 6

PAPs= 3’-phsophoadenosine and 5’-phosphosulfate, enzyme - sulfotransferase

Question 7

proteoglycans will be linked by-

Answer 7

linker proteins

Question 8

3 basic qualities of glycoproteins

Answer 8

branched
mannose rich
contain NANA

Question 9

where are carbohydrate chains added to glycoproteins?

Answer 9

serine or threonine residues

Question 10

what is dilichol phosphate?

Answer 10

involved in transferring branched sugar chains to the amide of asparagine

Question 11

I-cell disease

Answer 11

-caused by absence of mannose-6-P on lysosomal enzymes, they never reach lysosome, instead enter blood; substrates accumulate in lysosomes (def of n-acetylglucosamine phosphotransferase)

Question 12

2 sphingosine derivatives

Answer 12

cerebroside

ganglioside

Question 13

describe ganglioside

Answer 13

longer chains than cerebroside

Question 14

describe type A blood

Answer 14

GalNAc, enzyme = N-acetyl galactosamine transferase, anti-B antibodies

Question 15

describe type B blood

Answer 15

gal, enzyme = galactosyltransferase, anti-A antibodies

Question 16

describe type O blood,

Answer 16

no antigens, no enzymes, both anti-A and and-B antibodies

Question 17

describe type AB blood

Answer 17

both antigens, both enzymes, no antibodies

Question 18

mucopolysaccharidoses are caused by-

Answer 18

accumulation of partially degraded GAGs

Question 19

hunter syndrome

Answer 19

X linked
iduronate sulfatase def
H/D

Question 20

hurler syndrome

Answer 20

AR
a-L iduronidase def
H/D

Question 21

mucopolysaccharidosis type IV

Answer 21

AR
n-acetylglucosamine-4-sulfatase def
D/C

Question 22

nieman-pick

Answer 22

def sphingomyelinase

Question 23

tay-sachs

Answer 23

AR
mut in hexaminose A = decreased lipid degradation in lysosome that results in lipid accumulation “onion peel” and cherry red retina