Cytoskeleton

Question 0

Microfilaments

Answer 0

Thread-like protein fibers (7 nm), smallest filaments of the cytoskeleton and also most abundant. Composed of actin; actin molecules joined together in a twisted double-strand to form a microfilament. Actin monomers add to the plus end and disassembled at minus end. Their assembly is controlled by actin binding proteins

Question 1

Functions of cytoskeleton

Answer 1

Establishing cell shape, providing mechanical support, locomotion, intracellular transport of organelles and membrane vesicles, chromosome separation and cytokinesis - cell division

Question 2

Cytochalasin

Answer 2

Drug that depolymerizes Microfilaments

Question 3

Phalloidin

Answer 3

Drug that stabilizes microfilaments

Question 4

Blebbstatin

Answer 4

Drug that inhibits non-muscle myosin

Question 5

Intermediate filaments

Answer 5

Larger than Microfilaments but smaller than microtubules. Only part of the cytoskeleton that are not essential for survival. Join together as coiled-coil homodimer. Found throughout the cytoplasm and concentrated in a basket around the nucleus and at desmosomes

Question 6

Functions of intermediate filaments

Answer 6

Structural strength: prickle in skin, space fillers (axons of neurons), in epithelial cells are keratins, lamins are intermediate filaments in the nucleus, vimentin is an intermediate filament found in many cell types

Question 7

Microtubules

Answer 7

Cylindrical tubes and largest elements of cytoskeleton. Act as scaffolds to determine cell shape and provide tracks for cell organelles and vesicles to move along. Form spindle fibers for separating chromosomes during mitosis. They are nucleated at the MTOC, assembly at the plus end of by mechanism called dynamic instability. Associated and regulated with microtubule associated proteins.

Question 8

Cellular functions of microtubules

Answer 8

Structural rigidity, road map (motor proteins move along them), cell division, centrioles, motility

Question 9

Taxol

Answer 9

Stabilized microtubules and prevent disassembly

Question 10

Anti-mitotic drug

Answer 10

Destabilizes microtubules

Question 11

Monastrol

Answer 11

Inhibit kinesin motors