Biochem/histology Flashcards
adding more proteins to ECM makes it stronger/weaker?
stronger
drugs that affect microtubules?
- taxol (binds and stabilizes…cell does apoptosis)
- vinblastine, vincristine, colchicine, colcemid (bind to dimer, prevent polymerization)
drugs that affect microfilaments?
- phalloidin (binds and stabalizes)
- cytochalasin (binds to + end to prevent polymerization)
- latrunculin (binds to monomers, prevents polymerization)
ECM interacts with cells via?
transmembrane proteins
collagen undergoes what two processes in ER lumen?
hydroxylation of proline and lysine residues, glycosylation of some residues
what happens to procollagen when its in ECM?
enzymes cleave it, then it self assembles to collagen
what cofactor is important for collagen? why?
vitamin C bc it’s necessary for monomers to become polymers
what two diseases are associated with collagen?
scurvy (lack of cofactor vitamin C) and ehlers danlos syndrome (gene mutation)
gap junction is also known as a?
channel-forming junction
4 families of cell adhesion mcules (CAMs)?
cadherins, ig superfamily, selectins, integrins
what CAMs are dependent on Ca2+?
cadherins, selectins
E, N, VE cadherins interact with what? these cadherins are in what category?
actin cytoskeleton; classical
LI cadherins are atypical because?
don’t interact with actin sytoskeleton
which Ig superfamily CAMs are expressed on vascular endothelial cells and bind to integrin?
VCAM, ICAM, PECAM, NCAM
which Ig superfamily CAM is expressed on mucosal endothelium to direct lymphocyte entry into mucosa?
MAdCAM
what CAMs exhibit homo and heterophilic binding?
Ig superfamily
what CAMs don’t have a strong affinity?
selectins; this allows for rolling of cells
examples of integrins?
collagen, fibronectin, laminin
integrins via B2 family do what?
have cell to cell interactions
what enzyme to integrins interact with?
tyrosine kinase
epithelial functions?
protection, permeability, secretion, sensation (via nerves)
what is basement membrane necessary for?
diffusion of nutrients
proteins in tight junctions?
occludins, claudins
what occurs when you have tight junction problems?
blisters (fluid pools), food poisoning bacteria target TJs (leads to fluid in intestinal lumen), gastric ulcers (helicobacter pylori binds to TJs in stomach and increases permability)