Download Cytoskeleton and Cell Movement: An Overview of Protein Filaments and Their Functions and more Quizzes Cell Biology in PDF only on Docsity!
In what kind of cells is the cytoskeleton
found?
- Eukaroytic cells ONLY TERM 2
What is the cytoskeleton?
DEFINITION 2
- network of protein fibers w/in the cytosol- allows for intracellular transport, movement, change in shape & strength TERM 3
What are the 3 types of protein fibers and
where are they found?
DEFINITION 3
- Intermediate filaments: nuclear lamina nerve axons muscle cells epithelial cells
- Microtubules: centrosomes (microtub. organizing center)
- Actin filaments: Just below the PM as part of the cell cortex(muscle cells) TERM 4
Which protein filament is used in cell crawling
and phagocytosis?
DEFINITION 4
What are desmosomes?
DEFINITION 5 -cell structure specialized for cell-to-cell adhesion- allows skin cells to become sheets of skin tissue- intermediate filaments are involved in their formation
Intermediate Filaments
- rope like- long twisted strands of protein- toughest & most durable of all filaments- have ability to stretch (tensile strength) without rupturing- makes cytoskeleton stretch by not break- good for working out TERM 7
Microtubules
DEFINITION 7
- thickest of the filaments- long & stiff - hollow tubes (like a chinese finger trap)- repeating tubulin protein subunits- grows out of a centrosome TERM 8
Actin Filaments
DEFINITION 8
- thiniest- flexible but only has 2 strands wrapped around eachother and can break- responsible for cell movements phagocytosis: WBC engulfs debris/pathogen by pushing out PM extensions that surround the target
- capable of rapid assembly and disassembly (like microtubules)- can form permanent structures- network of actin & spectrin = support RBC shape TERM 9
What is progeria?
DEFINITION 9
- rare premature aging disorder- a defect in the nuclear lammina(lamins) of intermediate filaments causes this disorder wrinkled skin lose hair & teeth severe cardovascular dz by teens die young unknown cause (lack of NL may impair cell %, ^ cell death & diminish tissue repair) TERM 10
Which drugs interfere with microtubules?
DEFINITION 10 Colchicine: blocks development, kills %ing cell Taxol: interferes w/ mitosis by preventing microtubules from losing subunits
- cell dies because it is stuck in mitosis (apoptosis)- these two drugs are used to treat cancer
What are lamellipodia and filopodia?
lamellipodia: projections of thin sheets of PM filopodia: needle-like projections
- both are projections that aid in cell crawling TERM 17
What are motor protein and what are they
used for?
DEFINITION 17
- a class of molecular motors that use ATP to move along the surface of actin and microtubules (ex myosin)- they work alongside the microtubules to provide a vesicle/organelle movement. TERM 18
Can myosin bind to actin?
DEFINITION 18 YES TERM 19
What is myosin II used
in?
DEFINITION 19
- found in muscle - used for muscle contractions TERM 20
How does myosin I function in moving a PM?
DEFINITION 20 head binds to actin & pushes it along (heads are bound to PM) actin is then released head swings & rebinds to actin filament myosin stays stationary and actin is pushed overhead repeat
3 Steps in cell
crawling
actin is built at the leading edge to push membrane forward and create psudopods (lamellipodia and filopodia) pseudopods hit surface and adhere through integrins to actin remainder of cell is dragged behind anchor points
