Biology 6.6

Front 1

__________ is a network of fibers extending throughout the cytoplasm.

Back 1

cytoskeleton

Front 2

What are the three types of molecular structures of the cytoskeleton?

Back 2

microtubules, microfilaments, and intermediate filaments

Front 3

What are the 3 roles of the cytoskeleton?

Back 3

support, motility, and regulation

Front 4

Why is the support aspect of the cytoskeleton especially important in animal cells?

Back 4

they lack walls

Front 5

How is the cytoskeleton more dynamic than an animal skeleton?

Back 5

it can be dismantled in one part of the cell and reassembled in a new location, which changes the shape of the cell

Front 6

What 2 things is the term "cell motility" referring to?

Back 6

1) changes in cell location
2) limited movements of parts of the cell

Front 7

How are cytoskeletal elements and motor proteins involved in motility of a cell?

Back 7

The cytoskeletal elements and motor proteins work together with plasma membrane molecules to allow whole cells to move along fibers outside the cell

Front 8

_________ bring about the bending oc cilia and flagella by gripping microtubules within those organelles and sliding them against each other.

Back 8

motor proteins

Front 9

Where do vesicles and other organelles in a cell travel?

Back 9

along the cytoskeleton

Front 10

Out of microtubules, microfilaments, and intermediate filaments, which is the thickest?

Back 10

microtubules

Front 11

Out of microtubules, microfilaments, and intermediate filaments, which is the thinnest?

Back 11

microfilaments

Front 12

True or False: Some eukaryotic cells don't have microtubules.

Back 12

False. All eukaryotic cells have microtubules.

Front 13

Out of microtubules, microfilaments, and intermediate filaments, which is made up ot tubulin?

Back 13

microtubules

Front 14

Out of microtubules, microfilaments, and intermediate filaments, which is made up of actin?

Back 14

microfilaments

Front 15

Out of microtubules, microfilaments, and intermediate filaments, which is made up of one of several different properties of the keratin family?

Back 15

intermediate filament

Front 16

Out of microtubules, microfilaments, and intermediate filaments, which is made up of hollow tubes?

Back 16

microtubules

Front 17

Out of microtubules, microfilaments, and intermediate filaments, which is made up of two intertwined strans of actin?

Back 17

microfilaments

Front 18

Out of microtubules, microfilaments, and intermediate filaments, which is made up of fibrous proteins supercoiled into thicker cables?

Back 18

intermediate filaments

Front 19

Out of microtubules, microfilaments, and intermediate filaments, which is involved in the maintenance of the cell shape (compression-resisting "girders")?

Back 19

microtubules

Front 20

Out of microtubules, microfilaments, and intermediate filaments, which is involved in cell motility?

Back 20

microtubules

Front 21

Out of microtubules, microfilaments, and intermediate filaments, which is involved in chromosome movements in cell division?

Back 21

microtubules

Front 22

Out of microtubules, microfilaments, and intermediate filaments, which is involved in organelle movements?

Back 22

microtubules

Front 23

Out of microtubules, microfilaments, and intermediate filaments, which is involved in changes of the cell shape?

Back 23

microfilaments

Front 24

Out of microtubules, microfilaments, and intermediate filaments, which is involved in muscle contraction?

Back 24

microfilaments

Front 25

Out of microtubules, microfilaments, and intermediate filaments, which is involved in cytoplasmic streaming?

Back 25

microfilaments

Front 26

Out of microtubules, microfilaments, and intermediate filaments, which is involved in cell motility (as in psuedophodia)

Back 26

microfilaments

Front 27

Out of microtubules, microfilaments, and intermediate filaments, which is involved in cell division?

Back 27

microfilaments

Front 28

Out of microtubules, microfilaments, and intermediate filaments, which is involved in cleavage furrow formation?

Back 28

microfilaments

Front 29

Out of microtubules, microfilaments, and intermediate filaments, which is involved in maintenance of the cell shape (tension-bearing elements)?

Back 29

microfilaments and intermediate filaments

Front 30

Out of microtubules, microfilaments, and intermediate filaments, which is involved in the anchorage of nucleus and certain other organelle?

Back 30

intermediate filaments

Front 31

Out of microtubules, microfilaments, and intermediate filaments, which is involved in the formation of the nuclear lamina?

Back 31

intermediate filaments

Front 32

What are motor proteins?

Back 32

a protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell.

Front 33

What does it mean when we say that a tubulin protein is a dimer?

Back 33

it's a molecule made up of 2 subunits

Front 34

Are tubulins made up of polypeptides, polysaccharides, or fatty acids?

Back 34

polypeptides

Front 35

What are the types of tubulin?

Back 35

alpha-tubulin and beta-tubulin

Front 36

How do microtubules grow in length?

Back 36

my adding tubulin dimers.

Front 37

Microtubules can be assembled, but can they be disassembled?

Back 37

yes and their tubulin can be used to build microtubules elsewhere.

Front 38

Are the two ends of a microtubule the same or different?

Back 38

different

Front 39

True or False: the two ends of a microtubule release tubulin at equal rates.

Back 39

False. One end is much higher than another.

Front 40

True or False: the "plus end" of a microtubule is named so because it can ONLY add more tubulin proteins faster than the other end.

Back 40

False. it is also named so because its "on" and "off" rates are much higher than the other end.

Front 41

In animals cells, microtubules grow out from a _________.

Back 41

centrosome

Front 42

What is considered a "microtubule-organizing center"?

Back 42

centrosome

Front 43

What is the name of the microtubules that function as a compression-resisting girder of the cytoskeleton?

Back 43

centrosome

Front 44

Within the centrosome are a pair of ________.

Back 44

centrioles

Front 45

A centriole is composed of ____ sets of (single/double/triple) microtubules arranged in a _____ shape.

Back 45

nine, triple, ring

Front 46

When an animal cell divides, do the centrioles replicate before or after?

Back 46

before

Front 47

True or False: centrosomes are present in all cells that have microtubules.

Back 47

False. Yeast cells and plant cells lack centrosomes with centrioles but have well-organized microtubules.

Front 48

what makes up flagella and cilia?

Back 48

microtubules

Front 49

What is the tail of a sperm called?

Back 49

the flagella.

Front 50

True or False: Motile cilia are usually limited to one or a few per cell.

Back 50

False. motile cilia usually occur in large numbers on the cell surface.

Front 51

True or False: Flagella are usually thinner than motile cilia.

Back 51

False. They're the same diameter.

Front 52

True or False: Flagella are usually longer than cilia.

Back 52

true

Front 53

Does flagella have an undulating motion or like an oar?

Back 53

undulating

Front 54

Does motile cilia have an undulating motion or oar?

Back 54

Oar

Front 55

Which can act as a signal-receiving "antenna" for a cell, the cilia or flagella?

Back 55

cilia

Front 56

How many "antenna" are there per cell (if a cell does have one)?

Back 56

one. The cilia acts as an antenna.

Front 57

What do motile cilia and flagella share in common?

Back 57

Each has a core of microtubules that is an extension of the plasma membrane

Front 58

What exactly does the arrangement "9+2" represent?

Back 58

nine doublets of microtubules in a ring shape with two microtubules in the center.

Front 59

Which out of motile cilia, immotile cilia, and flagella have the"9+2" arrangement?

Back 59

motile cilia and flagella

Front 60

which out of motile cilia, immotile cilia and flagella have the "9+0" arrangement?

Back 60

immotile cilia

Front 61

What is a basal body?

Back 61

it anchors the motile cilia or flagellum to the cell.

Front 62

What is the basal body structurally similar to?

Back 62

a centriole

Front 63

What are dyneins composed of?

Back 63

several polypeptides

Front 64

What is responsible for the bending movement in organelle?

Back 64

dyeins

Front 65

What provides the energy for the dynein's movements?

Back 65

ATP

Front 66

Why don't the dyeins walk right off the microtubules?

Back 66

they're held in place by cross-linking proteins just inside the outer doublets and by radial spkes and other structural elements.

Front 67

What type of molecule is actin?

(hint: a type of protein)

Back 67

a globular protein

Front 68

Actin filaments are also known as _________

Back 68

microfilaments

Front 69

True or False: microfilaments are present in all eukaryotic cells.

Back 69

true.

Front 70

What enables microfilaments to form structural networks?

Back 70

the presence of proteins that bind along the side of the actin filaments.

Front 71

What is the structural role of microfilaments in the cytoskeleton?

Back 71

to bear tention (pulling forces)

Front 72

What is the name of the 3D network formed by microfilaments inside the plasma membrane?

Back 72

cortical microfilaments or cortex

Front 73

What is another name for cortical microfilaments?

Back 73

the cortex

Front 74

What does the cortex have a similar consistency to?

Back 74

gel

Front 75

What is the consistency of the interior cytoplasm?

Back 75

fluid (sol)

Front 76

What is the name of the network gives the outer cytoplasmic layer of a cell?

Back 76

the cortex

Front 77

Bundles of what make up the core of the microvili?

Back 77

microfilaments

Front 78

What is myosin?

Back 78

Like dynein, myosin acts as a microfilament-based motor protein by means of the projection "walk" along actin filaments

Front 79

_______ - ________ is responsible for localized contractions of cells (like dividing into two daughter cells.)

Back 79

actin-myosin

Front 80

_______ - ________ plays a role in amoeboid movement.

Back 80

Actin-myosin

Front 81

What is pseudopodia?

Back 81

when amoeboids have a sort of fake foot that helps them move which is from the actin-myosin

Front 82

In plant cells, both _____ - ______ and ___-_____ transformations brought about by actin may be involved in cytoplasmic streaming.

Back 82

actin-myosin , sol-gel

Front 83

What is cytoplasmic streaming?

Back 83

a circular flow of cytoplasm within the cell

Front 84

True or False: microtubules and microfilaments vary in diameter depending on the type of eukaryotic cell.

Back 84

False. They are all consistent in diameter and composition in all eukaryotic cells.

Front 85

True or False: Intermediate filaments are able to be assembled and dissasembled in different places.

Back 85

False. They are more permanent unlike microtubules and microfilaments.

Front 86

In cases where the shape of the entire cell is correlated with function,(microtubules, microfilaments, or intermediate filaments) support that shape.

Back 86

intermediate filaments