02.07 - The Cytoskeleton, Cell Motility and the Extracellular Matrix Flashcards
Which of the following is not a function of the cytoskeleton?
a. Cell motility
b. Structural support
c. Cytokinesis
d. None of the above.
d. None of the above.
Which is the first step in the assembly of microtubules?
a. Formation of protofilaments
b. Dimerization of alpha and beta tubulin units
c. Assembly of the microtubule cylinder
d. None of the above
b. Dimerization of alpha and beta tubulin units
Which statement does not describe microtubules?
a. Microtubules have polarity and are always in the state of dynamic instability.
b. Intracellular trafficking of vesicles depend on microtubules.
c. Microtubules are involved in the axoplasmic flow of material along neuronal processes.
d. Microtubules are made up of polypeptide chains arranged in a right-handed supercoil.
d. Microtubules are made up of polypeptide chains arranged in a right-handed supercoil.
Cilia is characterised by __________ movement; flagella is characterised by __________ movement.
Rotatory, undulatory
Which of the following statements is incorrect?
a. A flagella has a 9+2 arrangement of microfilaments.
b. The bending of cilia is driven by the motor protein dynein.
c. Cilia and flagella have the same ultrastructure.
d. Respiratory cells are lined with cilia.
a. A flagella has a 9+2 arrangement of microfilaments.
What is the principle behind the use of colchicine against gout?
a. Colchicine disassembles microtubules, facilitating the rearrangement of the cytoskeleton and thereby the movement of WBCs.
b. Colchicine inhibits the mitosis of the fungus causing gout.
c. Colchicine inhibits cellular division of WBCs.
d. Colchicine prevents microtubules from facilitating the movement of cells involved in the inflammatory response.
d. Colchicine prevents microtubules from facilitating the movement of cells involved in the inflammatory response.
This anti-fungal drug prevents fungal mitosis by inhibiting microtubules.
Griseofulvin
What syndrome results from the lack of the motor protein dyne in?
Kartagener Syndrome/Primary ciliary dyskinesia/Siewert’s Syndrome
Which does not occur in an individual with primary ciliary dyskinesia?
a. Inability of cilia to move debris out of the respiratory system
b. Improper migration of organs
c. Accelerated cellular ageing
d. Recurrent infections
c. Accelerated cellular aging
Which of the following statements is correct?
a. F-actin, a monomeric and globular protein, polymerizes to form a double helical filament.
b. G-actin polymerizes covalently to form the F-actin filament.
c. Localized contraction of actin-myosin aggregates drives amoeboid movement.
d. During contraction, actin molecules walk along the myosin filament, pulling stacks of myosin fiber together.
c. Localized contraction of actin-myosin aggregates drives amoeboid movement.
What triskelion-shaped protein facilitates receptor-mediated endocytosis during the internalization of LDL?
Clathrin
Which of the following does not apply to intermediate filaments?
a. Intermediate filaments have a diameter of 8-10 nm.
b. Intermediate filaments are more permanent and stable compared to microfilaments.
c. Intermediate filaments are rather deformable; they can be stretched several times their initial length.
d. Lamins are cytoplasmic intermediate filaments that is lacking in Hutchinson-Gilford progeria.
d. Lamins are cytoplasmic intermediate filaments that is lacking in Hutchinson-Gilford progeria. (Lamins are nuclear.)
Which of the following intermediate proteins is incorrectly paired with its distribution?
a. Lamins - nuclear lamina
b. Keratins - epithelial cells
c. Desmin - Glial cells
d. Peripherin - Neurons
c. Desmin - Glial cells (Desmin are found in muscle cells.)
What disease results from the mutations in the gene encoding lamin A and lamin C and is characterised by alopecia, prominent scalp veins, and accelerated ageing?
Hutchinson-Gilford Progeria
Mutations in genes encoding keratin results in a deficiency in the holding tension of the skin. This results into what disease?
Epidermolysis Bullosa Simplex