Flashcards in Lecture 5/ Chapter 5 Deck (45):
What is subunit of microtubules
subunit of microfilaments
subunit of intermediate filaments
lamins, keratin, meurofilamn, vimentin, desmin, GFAP
Relative size comparison of microtubues, microfilaments and IF
Biggest = Microtubules
Basic structure of microtubule--
alpha beta heterodimer. Polarized ends (protofilaments) The number that come together varies a lot.
Accessory proteins of Microtubules (2)
MAPs ( Microtubule associated proteins) example: Tau
What cytoskeletal structure transports organelles?
Dynein is what type of transport protein? What is the direction of movement?
Retrograde-- traveling from synapse back to the cell center
Kinesin is what type of transport protein? What is the direction of movement?
Orthograde-- cell center to the synapse
What is the hyperstable structure of the intermediate filament?
Desmosome and Hemidesmosome
What is the hyperstable structure of microfilaments? (there are two)
Sarcomere and Microvilli
What are the hyperstable structures of microtubules?
Cilia , flagella, and centrioles
What are the two motor proteins that play a role in microtubules?
Dyenein and Kinesin
What is the motor protein that plays a role in microfilaments?
What is the motor protein that plays a role in intermediate filaments?
There isn't one!!
What do dynein, kinesin, and myosin have in common?
They are all ATPase motor proteins
What are the organizers of the mitotic spindle called?
What are the functions of microtubules? (3)
1) cilia/flagella functions
2) mitotic spindle
3) organelle/cargo transport
What are the functions of microfilaments? (5)
3) Cell motility
4) Force generation (muscle)
5) Membrane stabilization-- as in RBC
What is the functions of intermediate filaments?
Mechanical integrity as in nucleus, cell-cell, matrix
What is the fastest dividing cell?
Drosophela every 15 mins (from lecture)
What are the two most important axoneme specialized MT based structures?
Flagella and cilia
Axonemes -- what is the motor molecule?
Dyenein is motor molecule
What is the molecular anatomy of the axoneme?
9+2 array (9 pairs on the outside and 1 pair on the inside)
What anchors flagella to the cell?
Basal body (it operates like a screw/ propeller)
Describe how cilia move? How does this differ from flagellar movement?
Cilia move w/ and effective and recovery stroke whereas a flagella is more of a propeller motion
What drugs target microtubules?
Taxol, Vica alkaloids (colchicine, vinblastine)
What anchors cilia?
Inside of a basal body, why is the inside filled w/ protein closest to the cell surface?
It serves as a very strong anchor
Kartageners (immotile cilia syndrome) cancer chemo, and dementias (tau-opathies) are medically relevant to what cytoskeletal structure?
How many dyenein arms per doublet pair on MT?
Kartagener's / Primary Ciliary Dyskinesia/ Immotile Cilia Syndrome
Hereditary Spherocytosis, Listeria infection, and Vaccinia are medically relevant to what cytoskeletal structure?
Laminopathies, blistering diseases, cancer diagnosis are medically relevant to what cytoskeletal structure?
What is the defect in immotile cilia sydrome
There is a deficiency in dyenein arms
What kind of drug is this? What is mechanism of action?
Chemothereapy tx. Can't escape from metaphase because mitotic spindle apparatus is not able to disassemble. "Freezes microtubules"
What is the difference between colchicine/ colcemid, Vinblastine, vincristine and taxol in terms of mechanism of action
The others--- Prevent actual assembly of microtubules
What is Tau protein
Accessory protein that regulates microtubule length.
What disease does Tau protein play a role in?
lamin is found in
all nucleated cells
keratin is found in
neurofilament is found in
vimentin is found in
mesenchymal, endothelial, fibroblast cells
desmin is found in