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49 Cards in this Set
- Front
- Back
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What are Rb and p53?
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Tumor suppressors that normally inhibit the G1-S transition
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What phase are stable/quiescent cells in, and what are examples of them?
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They are in G0 until stimulated to return to G1
e.g. hepatocytes, lymphocytes |
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What are labile cells?
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Rapidly dividing cells that never enter G0
e.g. bone marrow, gut epithelium, skin, hair follicles |
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What are Nissl bodies?
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RER in neurons
synthesize enzymes like choline acetyltransferase and peptide neurotransmitters |
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What happens at smooth ER?
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Steroid synthesis and drug detoxification
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What does the Golgi do to oligosaccharides?
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Modifies N on asparagine
Adds O on serine and threonine Adds mannose-6-phosphate |
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Which way does COPI traffic?
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retrograde
trans --> cis Golgi --> ER |
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Which way does COPII traffic?
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anterograde
cis --> trans ER --> Golgi |
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What causes I-cell disease?
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failure of addition of mannose-6-phosphate to lysosome proteins --> lysosomal storage disease
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What are features of I-cell disease?
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coarse features
clouded corneas restricted joints high plasma lysosomal enzymes death in childhood |
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What do peroxisomes do?
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Catabolism of very long fatty acids and AAs
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What is the structure of microtubules?
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helical polymerized alpha- and beta-tubulin
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Where are microtubules found?
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flagella, cilia, mitotic spindles, growing axons
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Which way do dynein and kinesin transport relative to the microtubule?
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dynein: retrograde to the microtubule
kinsein: anterograde to the microtubule |
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What do mebendazole and thiabendazole do?
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anti-helminthic
act on microtubules |
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What does Griseofulvan do?
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antifungal
acts on microtubules |
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What does vincristine/vinblastine do?
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anti-cancer
acts on microtubules |
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What does paclitaxel do?
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anti-breast cancer
acts on microtubules |
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What does colchicine do?
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anti-gout
acts on microtubules |
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What is Chediak-Higashi syndrome?
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decreased microtubule synthesis --> decreased phagosomes and lysosomes
--> pyogenic infections, albinism, peripheral neuropathy |
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What is the structure of cilia?
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9 + 2 microtubule arrangement
axonemal dynein ATPase that links doublets |
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What is Karatagener's syndrome?
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immotile cilia due to axonemal dynein arm defect
--> infertility, bronchiectasis, sinusitis situs inversus association |
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What do intermediate filaments do?
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Support cellular structure
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What does a stain for desmin show?
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Intermediate filaments in muscle
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What does higher cholesterol/long FA content in a cellular membrane do?
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increases melting temp and descreases flexibility
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What does a stain for vimentin show?
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intermediate filaments in connective tissue
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What does a stain for cytokeratin show?
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intermediate filaments in epithelia
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What does a stain for GFAP show?
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Intermediate filaments in neuroglia
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What does a stain for neurofilaments show?
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Intermediate filaments in neurons
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What is the exchange ratio of the Na-K-ATPase pump?
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1 ATP --> 3 Na out, 2 K in
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What does the poison ouabain do to the Na-K-ATPase?
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Inhibits the pump by binding to the K site
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What do cardiac glycosides (digoxin, digitoxin) do to the Na-K-ATPase pump?
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Direct inhibition of the pump --> indirect inhibition of Na/Ca exchange --> increased intracellular Ca and increased contractility
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Where is type I collagen found?
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bone, skin, tendons
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Where is type II collagen found?
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cartilage
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Where is type III collagen found?
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in reticulin
skin, blood vessels, uterus, fetal tissue, granulation tissue |
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Where is type IV collagen found?
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in basement membranes
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What causes Ehlers-Danlos syndrome?
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Defective type III collagen
(ThreE-D No crosslinks |
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What causes osteogenesis imperfecta?
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Defective type I collagen
No formation of procollagen triple helix |
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What causes Alport syndrome?
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Defective type IV collagen
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What is preprocollagen?
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alpha chains translated in the RER
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What does vitamin C do in collagen synthesis?
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allows hydroxylation of proline and lysine residues on preprocollagen
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What forms procollagen?
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Glycosilation of pro-alpha-chain hydroxylysine residues on preprocollagen and hydrogen-disulfide bonds allowing formation of a triple helix
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How is tropocollagen formed?
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Extracellular cleavage of terminal regions of procollagen and precipitation of the insoluble product
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What are features of osteogenesis imperfecta?
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multiple easily-formed fractures
blue sclerae hearing loss dental imperfections (lack of dentin) |
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What are features of Ehlers-Danlos syndrome?
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hyperextensible skin
easy bleeding/bruising hypermobile joints |
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What are features of Alport syndrome?
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progressive hereditary nephritis
deafness ocular problems |
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What does alpha-1 antitrypsin inhibit?
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elastase
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What causes Marfan's syndrome?
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A defect in fibrillin
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What are the two components of elastin?
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tropoelastin and fibrillin scaffolding
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