Cell biology VI Flashcards Preview

Year 1 Cell Biology > Cell biology VI > Flashcards

Flashcards in Cell biology VI Deck (55):
1

What is the role of microtubule-associated proteins?

Stabilize microtubules

2

What is the diameter of a microfilament?

6-8 nm

3

What are the subunits of microfilaments?

Actin

4

Actin subunits make up what cytoskeletal component?

Microfilaments

5

What drug inhibits polymerization of actin?

Cytocalasin B

6

What is the function of Cytocalasin B?

Prevents polymerization of actin subunits

7

What are the functions of microfilaments?

1) Structural support2) Form core of microvilli and stereocilia3) Cell movement4) Cytokinesis5) Formation of filopodia and lamellipodia

8

What is the diameter of thick filaments?

12-16 nm

9

What are the subunits of thick filaments?

Myosin

10

Myosin makes up which cytoskeletal component?

Thick filaments

11

What is the diameter of intermediate filaments?

About 10 nm

12

Cytokeratins are what kind of cytoskeletal component?

Intermediate filament

13

Desmin is what kind of cytoskeletal component?

Intermediate filament

14

Where are cytokeratins localized?

Epithelial cells

15

Where is desmin localized?

Muscle (smooth and striated)

16

Glial fibrillary acidic proteins (GFAPs) are what kind of cytoskeletal component?

Intermediate filament

17

Where are glial fibrillary acidic proteins (GFAPs) localized?

Astrocytic glial cells

18

Neurofilament proteins are what kind of cytoskeletal component?

Intermediate filament

19

Where are neurofilaments localized?

Neurons

20

Nuclear lamins are what kind of cytoskeletal component?

Intermediate filament

21

Where are nuclear lamins localized?

Nucleus of all cells

22

Vimentin is what kind of cytoskeletal component?

Intermediate filament

23

Where is vimentin localized?

Many mesodermal tissues

24

Mallory bodies are characteristic of what disease?

Alcoholic liver disease

25

Mallory bodies are made up of what type of intermediate filament?

Cytokeratins

26

Epidermolysis bullosa simplex is a disease characterized by lack of assembly of what intermediate filament?

Keratin

27

What do cytokeratins form?

Tonofilaments

28

Vimentin is found in what cell types?

1) Fibroblasts2) Chondroblasts

29

GFAP aggregates are observed in what diseases?

1) Alexander disease2) Chronic gliosis3) Astrocytomas

30

What are Rosenthal's fibers?

Aggregations of GFAPs

31

Pathologists can determine tumor type based on what cytoskeletal component?

Intermediate filaments

32

The centrosome (MTOC) conducts what microtubular processes / properties?

1) Number2) Polarity3) Direction4) Orientation5) Organization

33

What makes up the centrosome (MTOC)?

Two centrioles and an amorphous pericentriolar material

34

What is the arrangement of centrioles?

9x3 arrangement of microtubules

35

How are basal bodies formed?

Centrioles replicate to form procentrioles, which then become basal bodies

36

What are basal bodies required for?

Formation of microtubules associated with cilia and flagella

37

How is the centrosome involved in mitosis?

Formation of mitotic spindle

38

Are neoplastic cells with well-differentiated nuclei usually benign or malignant?

Benign

39

Are nuclei basophilic or acidophilic?

Basophilic

40

What are the components of the nucleus?

1) Nuclear envelope (double unit membrane)2) Nuclear matrix (nucleoplasm)3) Chromatin4) Nuclear bodies (domains)

41

What is the function of Cajal bodies?

Modification and assembly of molecular machinery to splice newly transcribed pre-mRNA into mRNA

42

What are GEMs?

Gemini of Cajal bodies

43

What is the cause of spinal muscular atrophy?

Mutation of survival of motor neurons (SMN) gene. SMN protein localizes to GEMs and causes death of motor neurons in anterior gray horns of spinal cord

44

What are PML bodies and what do they do?

1) Promyelocytic leukemia bodies2) Modify and assembly proteins involved in DNA repair and triggering of apoptosis

45

What is the diameter of a nuclear pore?

70 nm

46

How many subunits make up a nuclear pore?

8

47

What is the diameter limit for freely permeable molecules and ions passing through the nuclear pore?

48

The nuclear pore selectively transports what molecules?

1) RNA2) Ribosomal subunits3) Proteins4) Other molecules and ions

49

What are the functions of the nuclear lamina?

1) Supports inner nuclear membrane2) Disassembly of nuclear envelope during prometaphase - lamins are phosphorylated3) Reassembly of nuclear envelope during telophase - lamins are dephosphorylated

50

During disassembly of the nuclear envelope in prometaphase, are lamins phosphorylated or desphosphorylated?

Phosphorylated

51

During reassembly of the nuclear envelope in telophase, are lamins phosphorylated or desphosphorylated?

Dephosphrylated

52

Mutations in the nuclear lamina are associated with what diseases?

1) One form of muscular dystrophy2) Two forms of progeria

53

What is the basic structural unit of chromatin?

Nucleosome

54

Is heterochromatin transcriptionally active or inactive?

Inactive

55

Is euchromatin transcriptionally active or inactive?

Active