2 cellular Cytoskeletal elements Immunohistochemical stains for intermediate filaments Microtubule Cilia structure Plasma membrane composition Na/K pump Flashcards
What purposes do cilia, flagella, mitotic spindles, centrioles, and axonal trafficking serve? What cytoskeletal element do they all require?
Movement and cell division; microtubules
Name six compounds that are composed of intermediate filaments.
Vimentin, desmin, cytokeratin, lamins, glial fibrillary acid proteins (GFAP), neurofilaments
What is the prototypical microfilament that contributes to muscle contraction and cytokinesis?
Actin
Vimentin stains identify which type of cells?
Connective tissue
Which type of cell do desmin stains identify?
Muscle (desMin = Muscle)
Cytokeratin stains identify which type of cells?
Epithelial cells
Neurofilament stains identify which type of cells?
Neurons
What type of cell do glial fibrillary acid protein (GFAP) stains identify?
Neuroglia (GFAP = neuroGlia)
Name three cellular structures in which microtubules are found.
Cilia, flagella, and mitotic spindle
Microtubule filaments grow ____ (quickly/slowly) and collapse ____ (quickly/slowly).
Slowly; quickly
Are microtubules involved in fast or slow transport along the neuronal axons?
Slow axoplasmic transport
A man has recurrent attacks of acute inflammatory arthritis with a swollen big toe. What microtubule medication can abort an acute attack?
This is gout, treated with colchicine (inhibits microtubule polymerization by binding to tubulin)
Name three anticancer drugs that function by altering the polymerization of microtubules.
Vincristine, vinblastine, and paclitaxel
A patient has a fungal infection. You are asked to prescribe an antifungal agent that targets microtubules. What could you prescribe?
• Griseofulvin
Which antihelminthic drug targets the microtubules?
Mebendazole
• In a microtubule, ____ protein is for anterograde transport; ____ protein is for retrograde transport.
Kinesin (negative–to–positive end); dynein (positive–to–negative end)
Name two molecular motor proteins that transport cellular cargo to opposite ends of microtubule tracks.
Kinesin (anterograde transport) and dynein (retrograde transport)
Name the two protein constituents of the heterodimer building block for microtubules. How many GTPs are bound to each dimer?
α- and β-tubulin; each dimer is 2 GTP bound
How are cilia structurally composed?
Nine microtubule doublets around two central microtubules
What protein causes the movement of the cilia?
Axonemal dynein is an ATPase that links the nine peripheral doublets and causes cilia bending by differential sliding of doublets
Which diagnosis should you consider in a male patient with infertility, bronchiectasis, and recurrent sinusitis?
Kartagener syndrome (primary ciliary dyskinesia)
Can male or female patients, or both, have reduced fertility in Kartagener syndrome?
Both—immotile sperm in male patients; dysfunctional fallopian tube cilia and increased risk of ectopic pregnancy in females
A woman has a history of recurrent pneumonia; chest x-ray reveals dextrocardia. If she gets pregnant, what is she at risk for?
Kartagener syndrome (primary ciliary dyskinesia) in which dysfunctional fallopian tube cilia increase the risk for ectopic pregnancy
The plasma membrane is a(n) ____ (symmetric/asymmetric) lipid bilayer.
Asymmetric
Name five components of plasma membranes.
Phospholipids, cholesterol, sphingolipids, glycolipids, and proteins
How many ATPs are consumed in one cycle of the Na-K pump?
One
A man takes a drug that boosts cardiac contractility by indirectly raising intracellular Ca2+ levels. Blockade of which pump is responsible?
Cardiac glycosides inhibit Na+/K+ ATPase, causing decreased Na+/Ca2+ exchange and thus more intracellular Ca2+ (increased contractility)
Where does ouabain bind to the Na+-K+ ATPase? What does it do to the pump?
At the K+ binding site; it inhibits the pump
The ATP binding site of the Na+-K+ ATPase is located on the ____ side of the plasma membrane.
Cytosolic
For each ATP consumed by the Na+/K+ pump, three ____ (Na+/K+) ions go ____ (in/out) and two ____ (Na+/K+) ions go ____ (in/out).
Na+; out; K+; in
