Chapter 2- Cytosol/Cytoskeleton Flashcards
Where does metabolism happen in eukaryotic cells?
Nucleoplasm or membrane bound organells
Cytoskeleton is made of:
Protein fibers (actin microtub and int. fil) and accessory proteins (motor proteins)
Where do you see the transfer from nutrients in the gastro-tract to blood stream
apical / basolaterla surface
What molecule is double stranded and helical
actin
Describe the actin filaments
R. Handed ,
5-10nm ,
linear,
3D gels or 2D networks
Polymerisation>Hydrolysis
Hydrolysis>Polymerisation
+ end
- end
What type of cell surface projection are dynamic
Lamelopodia and filopodia
Microtobulues are :
Hollow long
25nm thick and they attach/start at the MTOC
What type of bonds bind the alpha and b-tubulins
covalent bonds, for the GTP molecule , only B side is hydrolyzed and exchangeable
how does a microtubule grow?
thru dynamic instability
what are type of intermediate filaments are there?
Nuclear lamins,
Kertins
Neurofilaments
Vimentins/Desmins
The following ways a cell can crawl
Protrusion
Attachments
Traction
Motor protein - type of filaments and role
Myosin=actin (C-terminus toward +end) = vesicle movement
Kinesin=Microtubules (N-terminus-toward +end) = cell divison
Dyneins=Microtubules(- end)
None are intermediate filaments = vesicle moving
Where is the major MTOC of the cell
The centrosome
what does the centrosome consist of
Centrosome matrix and 2 centrioles
Centriole is
9 fold symmetric with triples total of 27 microtobules
Centrosome matrix role
minus end formation of microtubule filaments
Intermediate filaments
Ropelike fiber
10nm
Structure of intermediate fialments
Made of many tetramers( ea/ tetramer is 2 dimers which is 2 monomer that are ea alpha helical)
What type of filaments is involved in cell-cell interaction and in adhesion jxn
Intermediate filaments
what motor proteins convert ATP energy into mechanical force
Dynenin and Kinesin
What type of cytoskleton direct intracell transport
microtubules
Filaments are builty from :
multiple protofilaments
How does polarity of actin grow
Plus end - dynamic unstable
Minus end - stable growth is towards the + end
which side has high rates of polymerizaiton
+ end
Which side has high rates of hydrolysis
- end
what bonds link microtobule structure
covalent bonds between alpha and b-tubulin
Treadmilling is seen in
Dinamic instability of microtubule growth
Addition of what structure permits continuous growth of microtobule
GTP-Cap
where is the center of microtubule growth
the centrosome
in what stage of cell cycle is MTOC seen
Mitosis - late prophase to metaphase
Where does the microtobule grow out of
y - gama tubulin ring complexes
