Protein trafficking Flashcards
What type of cells are rich in carbohydrates?
Epithelial cells- gut, lung, blood
What happens in the SER
Lipids are made here,
Vesicles form
What happens in the golgi?
Final addition of sugars and sorting
What are SRPs, what do they bind to and what do they do?
SRPs= signal recognition particle
SRPs bind to signal sequence on a polyp chain emerging from the ribosome
They guide the ribosome (and protein) to the translocator in the RER membrane
What goes through the translocator?
The protein- for translation to continue
What does signal peptidase do?
Removes signal peptides from secretory proteins
Whats a GPI anchor?
Glycolipid which anchors a protein to the cell membrane
3 important reasons for carbohydrate additions to proteins?
- Cross species separation- humans have beta-galactose
- Cell-cell recognition
- Protein stability in the harsh extracellular environment
What happens in the golgi cisternae?
Growth of carbohydrate chains- protein glycosylation
Each cisternae keep specific glycosylation enzymes away from each other
What determines human blood types? What are the features group O,A and B?
A single terminal galactose residue
O- lacks terminal galactose
A- acetylated galactose
B-normal galactose
What are the precursors of insulin?
Preproinsulin-> proinsulin-> insulin
What causes type 1 diabetes?
Misfolding of proinsulin in the ER due to a mutation-> secretion of dysfunctional proinsulin into the blood-> generation of antibodies against the pancreatic cells-> destruction of the pancreatic cells
What hormones can arise from opiomelanocortin
ACTH and beta-lipotropin from the pituitary gland
beta-endorphin from neurons
