Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MBOD Week 5 > Cytoskeleton I > Flashcards

Cytoskeleton I Flashcards

1
Q

What form the microvilli?

A

actin microfilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Besides forming microvilli on the apical surface of epithelium what is a major job of actin filaments?

A

Maintaining cell-cell junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What type of filaments extend from the nuclear envelope to the periphery of the cell?

A

intermediate filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T or F: intermediate filaments are very important in maintaining integrity of epithelial cells and muscle cells.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What filaments originate in a perinuclear fashion and extend to the periphery of the cell?

A

Mictotubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain the structure of the microtubule?

A

alpha and beta dimers combine at ± end to make 13 protofilaments that join to make a hollow tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T or F: in vitro tubulin can be placed into a tube and when it reaches a certain threshold concentration it polymerizes from positive and negative ends.

A

True - but growth at the + end proceeds much faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is always present in cells to induce microtubule formation?

A

some type of organizing center (site of nucleation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are nucleation sites needed in vivo?

A

Because cellular concentrations of tubulin are not high enough to induce spontaneous microtubule formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What part of the microtubule always inserts in the nucleation site and where on the nucleation site does it insert?

A

Negative (alpha) side of the tubule enters the gamma tubulin ring complexes on the centriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T or F: in the absence of any other chemicals as well as in the cellular environment, tubulin will sponaneously assemble and disassemble at the - end?

A

False, it will assemble and disassemble at the + end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens in a growing microtubule?

A
  • tubulin with bound GTP add to the end of the microtubule
  • addition of dimers proceeds faster than GTP hydrolysis
  • creates a GTP cap
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens in a shrinking microtubule?

A
  • Protofilaments containing GDP tubulin peel away from the microtubule wall
  • GDP tubulin is released to the cytosol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T or F: in the absence of any stimulation tubulin will undergo dynamic instability

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What family of motor proteins moves toward the positive end of microtubules?

A

Kinesins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What family of motor proteins moves to the minus end of microtubules?

A

Dyenins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the movement of globular heads in both motor proteins dependent on?

A

ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the determining factor for what type of cargo can be transported b motor proteins?

A

Their tale

19
Q

What situation garuntees and in tact microtubule?

A

GTP bound tubulin binding, exceeds the rate of tubulin hydrolysis

20
Q

T or F: bidirectional vesicles contain both dyeinin and kinesin?

A

T

21
Q

What feature of kinesin and dyeinin insures that they won’t fall off the microtubule track?

A
  • They have processive movement driven by ATP hydrolysis

- They always have one globular domain in contact with the MT

22
Q

What controls expansion and contraction of the ER?

A

Microtubules

ER follows them

23
Q

Explain the movement and motor proteins used in transport of proteins out of the ER, into the golgi and out of the cell

A

Kinesin - moves protein transport vesicle to ER exit site

Dynein - pulls vesicle into the Golgi

Kinesin - pushes the vesicles out of the golgi and out of the cell

24
Q

How does the golgi maintain its perinuclear position?

A

Dyneins

25
Q

Explain the arrangment of mircrotubules in cilia and flagella

A

9 (doublets) surrounding 2 singlets

26
Q

What do the 9 cytoplasmic doublets have?

A
  • ciliary dynein arms
  • nexin links
  • radial spokes
27
Q

What do the accessory proteins (those other than dynein and tubulin) do for the cilia?

A

They prevent sliding between microtubules and turn it into bending

28
Q

What is kartagener syndrome?

A

Defect of dynein heads

29
Q

T or F: defects in any of the ciliary proteins can cause defective cillia

A

T

30
Q

What is the roles of primary cilia?

A
  • chemo and mechanosensors
  • vital to embyonic development
  • COMPLETELY Immotile
31
Q

Where can primary cillia be found and what is their structure like?

A
  • Single ones are present on cells

- They contain no motor proteins, only 9 doublets and axoneme membrane

32
Q

What is the major check check point in mitosis?

A

Spindle attaches to chromosome on two different sides

33
Q

What happens to microtubules in interphase before mitosis, what is this dependent on?

A

they must shorten

-Action is dependent on catastrophins that destabilze and MAPs that stabilize microtubules

34
Q

What is the kinetochore?

A

Differentiated part of the centromere where kinetochore microtubules attach

-2 and both must be engaged for mitosis

35
Q

What protein joins sister chromatids?

A

cohesin

36
Q

What protein degrades cohesin?

A

separase

37
Q

What is anaphase A, what type of spindles are responsible?

A

Poleward movement of chromosomes that is depedent on shortening of KINETOCHORE mictrotubules

38
Q

What are the two phases of anaphase B?

A

Interpolar microtubules slide and lengthen using kinesin

aster microtubules pull using dynein at the same time

39
Q

What drugs bind the tubulin dimer and block assembly?

A

Vinblastin and vincristine

40
Q

What is anaphase A dependent on?

A

depolymerization of kinetochore microtubules of mitotic spindle

41
Q

T or F: taxol will have an effect on the ER in cells other than cancer.

A

True

42
Q

What classes of microtubules contribute to chromosome segregation?

A

interpolar, kinetochore, astral

43
Q

What is the most common type of mutation that effect dynamic instability?

A

Missence mutations

Other mutations are too detrimental

MBOD Week 5 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions