Unit 10: Cytoskeleton Flashcards
The skeleton is to bones as the cytoskeleton is to
a) ER
b) tubulin, actin and dynein
c) calcium
d) microtubules, microfilaments and intermediate filaments
e) plasma membrane
d)
Which of the following accurately represents how intermediate filaments differ from actin filaments and microtubules? Only intermediate filaments…
a) associate with motor proteins
b) interact with extracellular matrix components
c) are polar with plus and minus ends
d) are composed of the same protein subunits in all cells
e) play a purely structural role
e)
Which of the following motor proteins is associated with actin?
a) kinesin
b) myosin
c) dynein
d) a and c
e) a, b and c
b)
Which of the following statements about actin is FALSE?
a) Actin filaments interact with integrin proteins
b) Actin is involved in cytokinesis
c) Actin is typically the most abundant protein in an animal cell
d) Actin at the cell cortex helps govern the shape of the plasma membrane
e) Actin plays a role in the movement of cilia
e)
Cell motility involves the coordination of many events in the cell. In cells lacking flagella, which of the following phenomena are NOT required for cell motility?
a) myosin-mediated contraction at the rear of the moving cell
b) formation of plasma membrane extensions such as pseudopodia or filopodia
c) extension of actin filaments
d) formation of a microtubule array in the leading edge of the cell
e) integrin association with ECM proteins
d)
Researchers studied how vesicular transport occurs in cells by attempting to assemble the transport components. They set up microtubule tracks along which vesicles could be transported, and they added vesicles and ATP. Yet there was no movement of vesicles. What was missing?
a) an axon
b) ER
c) desmosomes
d) motor proteins
e) contractile microfilaments
d)
In general, if you treat cells with drugs such as colchicine that interfere with microtubules, which of the following are possible effects?
a) disruption of cell polarity
b) prevention of mitosis
c) abnormal localization of organelles
d) a and c
e) a, b and c
e)
The diversity of roles played by actin in the cell largely results from…
a) the variety of binding proteins that actin filaments can interact with
b) differences in the motor proteins that interact with actin
c) different isoforms of actin
d) variations in the way that the actin monomers polymerize
a)
The outer surface of your skin consists of…
a) epidermal epithelial cells joined by tight junction
b) keratin filaments packed into dead epidermal epithelial cells
c) mitotic epidermal epithelial cells
d) layers of actin filaments secreted by epidermal cells just before they died
e) a and c are true
b)
What is the most abundant protein within animal cells
a) tubulin
b) keratin
c) lamin
d) actin
e) flagellin
d)
Which type of cytoskeletal component would help reinforce the effectiveness of desmosomes in epithelial cells
a) microtubules
b) microfilaments
c) nuclear lamins
d) keratins
e) centrosomes
d) keratins
Colchicine is a compound that binds to tubulin, inhibiting microtubule polymerization. Which of the following would you expect to see in active dividing epithelial cells that have been exposed to this chemical?
a) disappearance of the mitochondria
b) impaired cell motility
c) an increased synthesis of microfilaments
d) leaky plasma membrane
e) failure of mitosis
e)
The transport of cargo (such as vesicles of secretory product) to the plasma membrane require
a) microtubules, kinesin, ATP
b) actin, myosin, ATP
c) keratin, dynein, ATP
d) microtubules, myosin, ATP
e) microfilaments, kinesin, ATP
a)
The diversity of functions of actin within the cell is due to
a) the different types of subunits that can make up the strands within a filament
b) the many ways actin polymers can be combined to form filaments
c) the different accessory proteins that can interact with actin filaments
d) differences in the chemical composition of the actin polymers
c)
The most important cytoskeletal component for motility of eukaryotic cells without flagella is
a) dynein
b) tubulin
c) keratin
d) actin
e) kinesin
d)
