The Cytoskeleton

Question 1

What does the cytoskeleton do?

Answer 1

gives the cell its shape and structure, and acts as a track for material transportation

Question 2

what are the three components of the cytoskeleton

Answer 2

microfilaments, microtubules, intermediate filaments

Question 3

microfilaments are rods made of:

Answer 3

actin (called actin filaments)

Question 4

actin filaments are organized into:

Answer 4

bundles and networks

Question 5

actin filaments are resistant to both:

Answer 5

compression and fracture

Question 6

because actin filaments are flexible, they can:

Answer 6

provide protection for the cell

Question 7

actin filaments can use ___ to generate force for movement

Answer 7

ATP

Question 8

actin filaments interact with ___ in muscle contractions

Answer 8

myosin

Question 9

microfilaments play a major role in which stage of mitosis?

Answer 9

cytokinesis - when the division of the daughter cells occurs

Question 10

during mitosis, the ___ ___ is formed from microfilaments

Answer 10

cleavage furrow

Question 11

what is a cleavage furrow?

Answer 11

formed from microfilaments, it is a ring that divides a cell into 2 daughter cells as the ring contracts

Question 12

are microfilaments solid or hollow?

Answer 12

solid

Question 13

are microtubules solid or hollow?

Answer 13

hollow

Question 14

microtubules are polymers of which proteins?

Answer 14

tubulin

Question 15

where are microtubules found in the cell?

Answer 15

they radiate far all over the cell

Question 16

what is the main purpose of microtubules

Answer 16

to act as pathways for motor proteins

Question 17

what are two major motor proteins that carry vesicles on microtubules

Answer 17

kinesin and dynein

Question 18

motor proteins like kinesin and dynein, as well as binding proteins, cell adhesion molecules, immunoglobulins, , and ion channels, are all examples of what?

Answer 18

nonenzymatic protein functions

Question 19

cilia and flagella are made up of

Answer 19

microtubules

Question 20

what are cilia?

Answer 20

projections from a cell mainly used in the movement of materials

Question 21

___ line the respiratory tract and are involved in the movement of mucus

Answer 21

cilia

Question 22

what are flagella?

Answer 22

structures that are mainly used to move an entire cell, like sperm

Question 23

cilia and flagella share the same structure, which is:

Answer 23

the 9+2 structure (only in eukaryotes)

9 microtubules on the outside, 2 on the center

Question 24

centrioles are found in a region of the cell called the:

Answer 24

centrosome

Question 25

what are centrioles?

Answer 25

organizing centers for microtubules

Question 26

how are centrioles structured?

Answer 26

nine triplets of microtubules with a hollow center

Question 27

what do centrioles do during mitosis?

Answer 27

migrate to opposite poles of the dividing cell and organize the mitotic spindle

Question 28

microtubules from centrioles attach to what part on a chromosome?

Answer 28

kinetochores

Question 29

what do the microtubules from centrioles do with chromosomes ultimately?

Answer 29

separate sister chromatids

Question 30

how many intermediate filaments are there? name some?

Answer 30

lots

keratin, desmin, vimentin, lamins

Question 31

what do most intermediate filaments do?

Answer 31

cell-cell adhesion or general cytoskeleton integrity

Question 32

how strong are intermediate filaments?

Answer 32

very strong, can withstand a lot of tension

Question 33

what helps to anchor organelles, including the nucleus

Answer 33

intermediate filaments

Question 34

what determines the identity of an intermediate filament protein?

Answer 34

it’s specific to cell and tissue type