The Dynamic Cytoskeleton: Chapter 7: pgs 141-147
Define the term cytoskeleton. Is the cytoskeleton static or dynamic? What does this mean?
What are three types of cytoskeletal filaments discussed in class? Which two resist tension (pulling force)? Which one
resists compression (pushing force)?
What does it mean to say that an actin filament has polarity? What is the structure of an actin filament?
What is myosin? Which cytoskeletal filament is it associated with?
How does myosin provide movement?
What are the three types of actin-mysoin filament based movements discussed in class.
Why do pseudopodia form during cell crawling? How does the process of cell crawling result in movement?
Actin-myosin filament based interactions cause what important part of cell division to happen? (Hint: think about a
“contractile ring”)
When two myosin tails are attached to each other forming a myosin filament, and the heads of these two myosin
molecules are attached to different actin filaments, what moves when the myosin head hydrolyzes ATP and initiates
movement? (HINT: it has to be either the myosin filament or the actin filament)
Intermediate filaments vary in composition, have no role in movement, and are involved in providing a “flexible skeleton”
to provide structural support to the cell. What two kinds, or examples, of intermediate filaments did we discuss in class?
What two things make microfilaments different than actin filaments? In what one way are they similar?
What is a centrosome? What is it composed of? Do you find these in both plant and animal cells?
What motor protein is associated with microtubules and the movement of vesicles? How does the structure of this protein
relate to its function? Does it move in a specific direction?
What are cilia? Flagella? Why is smoking bad from a cilia point of view?
How do eukaryotic and prokaryotic flagella differ in their movement?
How do prokaryotes “sense” their environment and then subsequently use their flagella to move?
What does the rotational direction of the prokarytotic flagellum or flagella determine?
How does the prokaryote use its flagella to move toward an attractant? A repellant?
What affects whether or not the bacteria have directed movement?
The “9+2 arrangement” refers to the structure of microtubules in an axoneme? In what cellular structure would you find
this arrangement?
What motor protein is associated with the movement of flagella? How does it work?
What is the purpose of having cytoplasmic dynein?
