Molecular biochem and genetics Flashcards Preview

Boards microbio and biochem > Molecular biochem and genetics > Flashcards

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


Kartagener syndrome

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?

connective tissue


What does desmin stain for?



What does cytokeratin stain for?

epithelial cells


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)


Menkes disease

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.


microtubules vs. cilia vs intermediate filaments

microtubules: helical array of alpha and beta tubulin heterodimers. used for MOVEMENT: flagella, cilia, mitotic spindles, slow axonal transport. cilia have 9+2 arrangement of microtubles (other small details but I may not learn them)
intermediate tubules: used for STRUCTURE, and important becasue we stain them (GFAP, vimentin, desmin, cytokeratin, etc).