Biochem 77 Flashcards
The golgi apparatus modifies N-oligosacharrides on which amino acid residue?
Aparagine
The golgi apparatus ADDS O-oligosacharrides on which 2 amino acids?
- Serine
- Threonine
What does the golgi apparatus add to proteins for trafficking to lysosomes?
Mannose-6-phosphate
What type of disorder is I-cell disease?
Lysosomal storage disorder
What is the defective enzyme in I-cell disease?
Phosphotransferase
What is the result of the deficient enzyme in I-cell disease?
Failure of Golgi to phosphorylate mannose residues on glycoproteins -> proteins are secreted extracellularily instead of delivered to lysosomes
What are the signs of I-cell disease? (4)
1) Course facial features
2) Clouded cornea
3) Restricted joint movement
4) Elevated lysosomal enzymes in blood
What are signal recognition particles (SRP)?
Abundant cytoplasmic ribonucleotide that transports proteins from ribosome to RER. (such as in collagen synthesis)
What occurs when there is absent or defective SRP?
protein accumulation in cytosol.
What are the 3 vesicular trafficking proteins?
1) COP I
2) COP II
3) Clatharin
What is the function of Clatharin.
Trans-golgi transport to lysosomes
Cell surface to endosomes (receptor mediated endocytosis)
What is an example of receptor mediated endocytosis?
LDL receptor activity
What is the function of COP I?
Golgi -> golgi (retrograde)
Golgi -> ER
What is the function of COP II?
Golgi -> golgi (anterograde)
ER -> Golgi
Peroxisomes are involved in the catabolism of what? (3)
1) Very long chain fatty acids
2) Branched chain fatty acids
3) Amino acids
