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Flashcards in Biochemistry Deck (173)
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1

Another name for a proteoglycan

Sugar backbone + protein
Mucopolysaccharide

2

A GAG consists of

Repeating disaccharide units of: acid sugar (glucuronic acid, iduronic acid) & amino sugar (glucosamine, galactosamine)

3

6 major groups of GAG include:

1. CS #1 (cartilage, bone, heart valves)
2. Hyaluronic acid (no sulfate, not covalently attached to proteins)
3. KS
4. DS
5. Heparan Sulfate (negatively charged, acetylated glucosamine)
6. Heparin (more sulfated than HS)

4

Cartilage consists of these GAGs (3)

CS, KS, hyaluronic acid

5

How is a GAG linked to a protein to form a proteoglycan?

Trihexoside linkage (gal-gal-xy) + serine

6

GAG's are synthesized using what enzymes

Glycosyl transferases

7

Who is the sulfate donor when it comes to proteoglycan synthesis?

PAPS (with sulfrotransferase)

8

What is I cell disease?

Inability to transport hydrolytic enzymes to lysosomes 2/2 to inability to phosphorylate mannose
* Skeletal abnormalities, psychomotor, no joint movement
* Substances accumulate in lysosome; enzymes accumulate in plasma

9

O-glycosidic links in glycoproteins are made by...

OH- of serine/threonine

10

What are several examples of glycoproteins?

Cell surface receptors, blood group Ag, collagen, fibronectin

11

The pathogenesis of E. coli & H. pylori as it relates to glycoproteins

E. coli: mannose in plasma membrane
H. pylori: gastric epithelium

12

COPI vs COP2 cellular trafficking
What about clathrin?

COP1: retrograde: Golgi --> ER
COP2: anterograde: ER --> Golgi
Clathrin: Golgi --> Lysosomes; Plasma membrane --> Endosomes

13

What GAG can be injected into the joints of patients with osteoarthritis?

Hyaluronic acid

14

Fabry's disease: deficient enzyme

Alpha-galactosidase

15

Gaucher's disease: deficient enzyme

Glucocerebrosidase

16

Niemann-Pick disease: deficient enzyme

Sphingomyelinase

17

Tay-Sachs disease: deficient enzyme

Hexosaminidase A

18

Krabbe's disease: deficient enzyme

Galactocerebrosidase

19

Metachromatic leukodystrophy: deficient enzyme

Aryl sulfatase

20

Hurler's syndrome: deficient enzyme

Alpha-L-iduronidase

21

Hunter's syndrome: deficient enzyme

Iduronate sulfatase

22

X-linked lysosomal storage disorders

Hunter's, Fabry's

23

Cherry-red spot macula lysosomal storage disorders

Tay-Sachs, Niemann-Pick (+HSM)

24

Corneal clouding lysosomal storage disorders

Hurler's disease

25

Fabry's disease: accumulated substrate

Ceramide trihexoside

26

Gaucher's disease: accumulated substrate

Glucocerebroside

27

Niemann-Pick disease: accumulated substrate

Sphingomyelinase

28

Tay-Sachs disease: accumulated substrate

GM2 ganglioside

29

Krabbe's disease: accumulated substrate

Galacrocerebroside

30

Metachromatic leukodystrophy: accumulated substrate

Cerebroside sulfate