Biochem

Question 1

I cell disease

Answer 1

failure of Golgi to phosphorylate mannose residues = proteins cannot be delivered to lysosomes

Question 2

I cell disease features:

Answer 2

coarse facial features, gingival hyperplasia, clouded corneas, restricted joint movements, claw hand deformities, kyphoscoliosis, and high plasma levels of lysosomal enzymes. Often fatal in childhood.

Question 3

Zellweger syndrome

Answer 3

AR disorder of peroxisome biogenesis due to mutated PEX genes. Hypotonia, seizures, hepatomegaly, early death.

Question 4

Refsum disease

Answer 4

AR disorder of alpha oxidation= phytanic acid not metabolized to pristanic acid.
Scaly skin, ataxia, cataracts/night blindness, shortening of 4th toe, epiphyseal dysplasia.
treatment: diet, plasmapheresis

Question 5

Adrenoleukodystrophy

Answer 5

x-linked recessive disorder of beta oxidation = VLCFA buildup in adrenal glands, white matter of brain, testes. Progressive disease that can lead to adrenal gland crisis, coma and death.

Question 6

Peroxisomes function

Answer 6

Alpha oxidation
beta oxidation of VLCFA
catabolism of branched chain fatty acids, amino acids and ethanol
synthesis of bile, cholesterol and plasmalogens