organelle

Question 1

what are the 3 functions of the golgi apparatus?

Answer 1

1. modify new proteins for lysosomes, secretion and plasma membrane
2. packages enzymes for lysosomes and proteins for secretion
3. sorts material for lysosomes, secretion and incorporation into plasma membrane

Question 2

What is I cell disease?

Answer 2

there is a deficiency in phosphorylating enzyme GlcNac-1-phosphotransferase. causes lysosomal enzymes coming from the RER NOT to be phosphorylated in the golgi apparatus
THEREFORE these enzymes are not directed to the lysosomes because they are unphosphorylated and leave the cell and accumulate in patient’s blood.
lysosome doesn’t get the enzymes it needs, so there is accumulation of undegraded proteins in the blood.

Question 3

what causes mitochondrial myopathies?

Answer 3

neuromuscular disease: muscle fibers sensitive due to mutations in the mitochondrial dna or nuclear dna
(mitochondrial dna has higher mutation rate than ndna due to no dna repair mechanism)
sx: drooping of eyelid, dysphagia, limb weakness, but no presentation until mutant mtDNA/normal mtDNA ratio is high