histo 7

Question 1

what is the cytoskeleton ?

Answer 1

a complex array of
microtubules, microfilaments
and intermediate filaments.

Question 2

whta is the fuction of the cytoskeleton ?

Answer 2

determine the shapes of cells, play an important role in the movements of organelles and cytoplasmic vesicles, and also allow
the movement of entire cells

Question 3

what is the axonemes ?

Answer 3

cytoplasmic extensions called cilia and flagella with an outer
diameter of 25 nm and a wall 5-nm thick, a structure that confers significant rigidity to help maintain cell shape

Question 4

what is the protein subunit of a microtubule ?

Answer 4

a heterodimer of α and β tubulin

Question 5

Polymerization of tubulins is directed by what ?

Answer 5

microtubule organizing centers and the growth occurring more rapidly at the (+) end

Question 6

steady-state conditions, which depend on what?

Answer 6

concentrations of
tubulin, Ca2+, Mg2+, and the presence of microtubule associated proteins (MAPs)

Question 7

what is the most dominant MTOC in the cells ?

Answer 7

centrosome,
which is organized around two cylindrical centrioles

Question 8

Microfilaments are composed of what ?

Answer 8

actin subunits

Question 9

what is the function of the microfilaments

Answer 9

motility and most contractile activity in cells