‼️BIOCHEM-Special Topics Flashcards
Examples of acidic sugars
Glucuronic acid
Iduronic acid
GAG in mast cells
Heparin
All GAGs are attached to proteins to form
Proteoglycans
GAG located at sites of calcification in endochondral bone and are also found in cartilage
Chondroitin sulfate
GAGs that play a role in corneal transparency
Keratan sulfate I and dermatan sulfate
GAG Structural role in sclera
Dermatan sulfate
Heparin binds with factors
IX and XI
GAG that determines the charge selectiveness of renal glomerulus
Heparan sulfate
Synthesis of GAGs occur in which organelles?
ER and golgi apparatus
How are GAGs degraded?
They are phagocytosed and vesicles fuse with lysosomes where they are degraded
Lysosomal degradationof GAGs are accomplished by
Acid hydrolases
Accumulation of GAGs in lysosomes due to deficiency in hydrolases
Mucopolysaccharidoses
All mucopolysaccharidoses are autosomal recessive except for
Hunter’s syndrome (x-linked recessive)
All mucopolysaccharidoses have mental retardation except
Morquio’s syndrome
No CNS involvement
Mucopolysaccharidoseses with deficiency in alpha L iduronidase
Hurler’s and Scheie’s syndrome
Type VII mucopolysaccharidoses
Enzyme deficiency?
Sly syndrome
Beta glucoronidase
Type II mucopolysaccharidoses
Enzyme deficient?
Hunter’s syndrome
Iduronate sulfatase
Type III mucopolysaccharidoses
Sanfilippo syndrome
Morquio’s syndrome is deficient in
Galactose 6 sulfatase
Proteins to which oligosaccharides are covalently attached
Glycoproteins
Length of carbohydrate chain in gycoprotein is relatively
Vs proteoglycans
Short and branched
Proteoglycans: linear and longer
Sugar units in glycoproteins vs proteoglycans
GP - NO repeating sugar units
PG- WITH repeating sugar units
Major classes of glycoproteins
O- linked
N-linked
GPI-linked
O-linked glycoproteins are bound to which amino acids
Serine and threonine
N-linked glycoproteins are bound to what amino acid?
Asparagine
Production of O-linked vs N-linked Glycoprotein
O-linked gOlgi apparatus
N-linked eNdoplasmic ret
R group
O-linked vs N-linked
o- hydroxyl
n- amide
Glycosaminoglycans are generally composed of
Repeating disaccharide units
Amino sugar
Acidic sugar
