Flashcards in Molecular biochem and genetics Deck (16):
Dynein vs. kinesin
motor proteins. dynein goes retrograde to the micgrotubule (away from the direction it is being built); kinesin goes anterograde to the microtubule
primary ciliary dyskinesia. an immotile cilia d/t a dynein (retrograde wrt the microtubule) arm defect. bronchiectasis, recurrent sinusitis, situs inversus, infertility
What drugs affect the microtubules?
(microtubles get constructed very poorly):
mebendazole, griseofulvan (anti-fungal), colchicine, vincristine/vinblastine, paclitaxel (anti-CA)
What does vimentin stain for?
What does desmin stain for?
What does cytokeratin stain for?
Sodium potassium pump and cxn to pharm
maintains the normal electrochemical gradient. pumps 3 Na out and brings 2 K in. costs 1 ATP. Digoxin works by reducing the function of the Na/K/ATPase. Recall that, in heart cells, the Na/K/ATPase pump is tied to a Na/Ca exchanger. The Na/Ca exchanger moves an Na in (along its gradient) and a Ca out. When the electrochemical gradient isn't as well established, the Ca will stay in the heart cell longer, thus increasing contractility.
What diseases are associated with types I, III, and IV cartilage?
I: osteogenesis imperfecta
III: vascular Ehlers-Danlos syndrome
IV: target of goodpasteurs, defective in Alport syndrome (kidney disease, hearing loss, and eye problems, usually inherited in an X-linked fashion but may be autosomal recessive)
Steps to collagen synthesis; diseases that affect each step
synthesis, hydroxylation (vitamin C deficiency), glycosylation (important for formation of a procollagen and a triple helix. If you can't form the triple helix, you have osteogenesis imperfect) (all in the RER), then exocytosis. outside of fibroblasts, there is proteolytic processing and cross-linking (Copper deficiency, Ehlers-Danlos)
Osteogenesis imperfecta manifestations
blue sclera, hearing loss from abnormal ossicles, dental imperfections, lots of fractures. usually autosomal dominant, often from decr. production of type I collagen
Symptoms of Ehler's danlos syndrome
easy bruisng, hypermobile joints, joint dislocation, berry aneurysms, and organ rupture.
many types, all due to problems with collagen cross linking
Classic Ehler's Dnalos vs. vascular Ehler's danlos
classic: joint and skin symptoms d/t type V collagen mutation. vascular: vascular symptoms and organ rupture d/t defects with type III collagen (which helps form blood vessels)
problems with copper absorption and transport. causes intellectual disability, growth problems, hypotonia, and kinky, brittle hair.
decr. activity of lysyl oxidase (enzyme critical for collagen cross-linking)
Elastin: important amino acids
proline and glycine. involves tropoelastin with fibrillin scaffolding. crosslinking also important (extra-cellular). broken down by elastase, which is normally inhibited by alpha-1 antitrypsin.
alpha-1-antitrypsin deficiency can cause emphysema and liver disease. problems with fibrillin sheak cause marfan syndrome.
CDKs vs. cyclins
CDKs: cyclin dependant kinases that are CONSTITUTIVE and INACTIVE.
cyclins: regulatory proteins that control cell cycle events, are phase specific, and activate CDKs.