Cellular Biochemistry Flashcards
What is defective in I-cell disease?
Phosphotransferase, enzyme in golgi bodies that normally phosphorylates mannose to mannose-6-P
What are the classic symptoms of I-cell disease?
- Coarse facial features
- Clouded corneas
- Restricted joint movement
- High plasma levels of lysosomal enzymes
What results from an absence of mannose-6-P on proteins?
Mannose-6-P is a tag that sends proteins to the lysosome, so without it lysosomal enzymes are secreted to the extracellular space
What is the function of the peroxisome?
-Breaks down very long chain fatty acids, branched-chain fatty acids and AA
What is the function of the proteasome?
Degrades damaged and ubiquitin tagged proteins
What causes Kartagener syndrome?
Immotile cilia from defective dynein arm
What are the typical symptoms of Kartagener syndrome?
- Infertility
- Bronchiectasis
- Recurrent sinusitis
- Situs invertus
What does vimentin stain for?
Connective tissue
What does Demin stain for?
Muscle
What does cytoketatin stain for?
Epithelial cells
What does GFAP stain for?
Neuroglia
What are the 6 steps to making collagen, and where do they occur?
- Synthesis (fibroblast RER) = Gly + Lys+ Pro
- Hydroxylation (fibroblast RER) = of Lys+Pro Needs vit C
- Glycosylation (fibroblast RER) = Makes triple helix
- Exocytosis (fibroblast)
- Proteolytic processing = Procollagen -> Tropocollagen
- Cross-linking = Covalent
What disease results from faulty cross linking of collagen?
Ehlers-Danlos syndrome
Blue sclera + Fractures + Hearing loss + Dental imperfections
Osteogenesis imperfecta, decreased type 1 collagen formation
What is the typical presentation of Ehlers-Danlos syndrome?
- Hyperextensible skin
- Easy bruising
- Hypermobile joints, join dislocation
- Berry and aortic aneurysms
- Organ rupture
