Brainscape's Knowledge GenomeTM

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


See full index

Biology > Actin and Myosin in Non-skeletal muscle cells > Flashcards

Actin and Myosin in Non-skeletal muscle cells Flashcards

1
Q

What are 5 examples of actin and myosin in non skeletal muscle cells

A

Cytokinesis
Smooth muscle
Vesicle transport
Cytoplasmic streaming
cell migration

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

What is seen in contractile rings

A

Actin myosin orginzation is seen in contractile rings gets smaller smaller by de polymerizing

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

Where is smooth muscle contraction present

A

Arteries and intestines and is not voulntary

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

What is relaxation

A

When the myosin is folded and inactive

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

How does Calcium play a role in smooth muscle contraction

A

When it is present it activates a kinase CaM which goes to phosphorylate Myosin light chain that will activate myosin heavy chain that can now hold onto the actin

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

What a regulator of smooth muscle contraction

A

Myosin phosphorylation

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

Whats the difference between smooth muscle contraction and skeletal muscle

A

Smooth muscle is much slower and more persistent contaction than skeletal muscle also there is no troponin and tropmyosin so it can last for much longer

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

What are Myosin V bound vesicles

A

They are carried along actin fillaments

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

When is myosin v unactive

A

When there is no cargo

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

Why do you want the nucleus to be close to the bud

A

Because half of its DNA goes into the daughter cell

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

What is the actin doing in a yeast buding cell

A

It provides a pathway that leads into the bud

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

what transports structures get into the bud

A

Myosin 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What capps the actin

A

Formin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What postions the nucleus

A

MT

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

Which way is the actin polymerzing

A

It is growing in the negative end so the positive end stays in the bud

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

Where does cytoplasmic streaming occur

A

Usually occurs in plant cells and helps with difuusion can occur in us but not for diffusion

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

What filopodia formation

A

Finger like projections from bundles

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

What is lamellipodia formation

A

Large movement of actin pushed from networks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do membranes move forward

A

Because the actin is polymerzing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are fochal adhesions

A

Serve as anchoring points for actin filaments providing structural support and enabling cells to respond to their enviorment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are integrins

A

Involves trans membrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does Cyclo and cAMP do on the cell surface

A

Tell s the cell where to go and moves the cell to a high concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a receptor

A

It is around the entire cell because the cell has to know where to go

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where is the direction going to go

A

Towards high concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What happens when the ligand binds

A

Binds to the receptor which then turn activates the associated G protien

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where is actin and mysoin on the cell

A

Actin is in the front form the lamellipodium pushes it forward and myosin is in the back stress fibers that push the back of the cell forward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 4 steps of cell movement

A

Step one which is extension you have a stress fiber inbetween each focal adhesion
the actin polymerizes and the membrane will extend
Step 2 the new adhestion is formed along with a new stress fiber
Step 3 It then translocates forward actin and myosin interact with each other and move the cell body forward
Step 4 is de-adhesion is where you really move the cell bringing th ehead and tail forward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is Cdc42 rac and rho

A

They are all RHo protiens which is memebrs of the RAS superfamily of small GTPASE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What do GTP in active form trigger

A

Effecteor protiens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens if you have a dominant active Rac

A

The whole membrane ruffle lamellipodia at one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What happens if you have dominant Cdc42

A

Lots of fillpodium made

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens if you have domminant active RHO

A

Activate formin causes unbranched actin get long acting bundles that are SF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does Cdc 42

A

Works with wasp and then that activates Arp23 which creates actin polymerization and then

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does Cdc42 do once it is activated

A

It is activated first and then go to activate rac GTP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does Rac GTP activate

A

Goes to turn on WAVE then Arp 2/3 and actin polymerization to form lamellipodia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does Rho GTP activate

A

Formin which causes actin polymerization that makes stress fiber formation and contraction also activates Myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What Rho protien contributes to polarity

A

Cdc42

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Are they the same in migratory and non migarotry cells

A

In migaratory cells they have a sighlty different function

39
Q

How many do you need to work together

A

3

40
Q

What happens if you have Cdc42 activation at the front

A

Leads to front activation of rac leading to arp 2/3 activation and Roh back is leading to myosin 2 activation

41
Q

What are functions of intermediate filaments

A
  • Not globular
    No Atp or GTP needed
    No polarity
    No known motor protiens
    Less dynamic
    Tetramer is the basic sub unit
42
Q

What are the types of intermediate epithelia cells

A

Acidic keratins and basic kertains
Contribute to tissue strength and intergrity

43
Q

What are class 3 of intermediate fillaments

A

Desmin are intergrity to muscle celss striated and smooth
Vimentin found in migrating cells and mesenchymal cells

44
Q

What is class 4 of intermediate filaments

A

Neurofilaments
Found in neurons
Structure to axons

45
Q

What is class five of intermediate filaments

A

Lamins
Not cell type specific
Provides support to the nucleus
Inter membrane is filled with them

46
Q

What are the point of intermediate fillaments

A

They are organizational protiens microtubules link to them and the have protiens that can bind to them and hold them in place provide structural support for cell shape

47
Q

What does vimetin do

A

Links to aankyrin at plasma membrane

48
Q

What do Lamins A b and C do

A

Support the nuclear membrane

49
Q

What are B lamins

A

Ubiquitous and linked via prenylation

50
Q

What state are IFs in

A

They are in a dynamic state

51
Q

What happens when something polymerizes

A

Cells need to regualte and get rid of the nuclear membrane have to get rid of lamina A

52
Q

How does lamin disasemble

A

N terminal domain of lamin A phosphorylated at serine and prevents reassbley if the serien residue mutated no disassembly

53
Q

What is lamina A for

A

The nuclear membrane if you want to go under mitosis it has to disassemble

54
Q

What are IFs crucial too

What type of tissue

A

Epithelia and other tissue integrity this is why the skin does not break

55
Q

What holds the epidermis and dermis together

A

Kertain

56
Q

What do transgenic mice carrying a mutant kertain gene exhibt

A

Skin blistering

57
Q

What are desmosomes

A

Cell to cell adhesions that are supported by keartain

58
Q

What are hemidesmoses

A

Cell to extracellular matrix

59
Q

What are the 4 types of cell adhesions

A

Tight junctions
Gap junctions
Cell-cell adhesions
Cell- ECM adhesions

60
Q

What are tight junctions

A

Not bound to the cytoskeltons so they do not contribute srength they restrict what basses between cells
You want to make sure that material does not go through the cell and sneak in between

61
Q

What are the three types of tight junctions

A

JAM
Occludin
Caludin

62
Q

What are gap junctions

What are they formed by

A

Also do not contribute to stength
Formed by 6 connexins to form a connexon
Small molecules such as ions can flow through these chanels
Different molecules pass through dependent on what type of conexon
Channels between adjacent cells

63
Q

What happens when you damage one cell

A

You have to close the gap junction

64
Q

What is gap junctions dependent on

A

Ca concentration if the cells is damages because there is not alot of Ca inside the cell normally

65
Q

What are Ig superfamily of CAMS

A

Cell-cells adhesion
Homophilic interacations are the same molecules

66
Q

What are homophilic interacations

A

Same molecules and it is cell to cell Cadherins and Ig superfamily (Cams)

67
Q

What are heterophilic interacations

A

two different molecules binding together example Intergrins and selectins

68
Q

What is the Ig superfamily

A

Mediate Ca independent (bind cells together independent of Ca) homophilic adhesion same tissue will have the same superfamily so they can stick together

69
Q

What are Major cadherin molecules

What types of tissues

A

Single transmembrane domain and cytosolic C terminal tail associated with the cytoskeleton
Ca dependent
Need the extracellular calcium
Essisental for holding cells in sheets
Epidermal tissues
Nervous tissues

70
Q

How to tell the difference

A

If you remove calcium and it still binds it is a superfamily need the same one ot bind cells together

71
Q

What are cadherins dependent on

Other than calcium

A

Cytoskeletal elements the cytopplasmic domain interacts with the cytoskeletal and depends on what part of the cytoskelton it binds to

72
Q

What will it do if it binds to a IF like keratin

A

Form a desmosome

73
Q

what will form if cadherin binds to binds to F actin

A

Adheren junctions can form a belt and become contractile also for cell movement

74
Q

What does F actin do

A

Comes together to form the circumferential belt that can become contractile

75
Q

Why do celladhesions link to the cytoskeleton

A

To allow signaling cells will know if they are linked to each other or not this will single to cell nucleus if things are broken

76
Q

What is the extra cellular matrix

A

Mix of secreted molecules that all cells interact with and regulates many cellular functions

77
Q

what are the functions of ECM

A
  1. Anchorning and surriounding cells to maintain soild tissue
  2. Determening the biomechanical properties of the extracellular enviornment
  3. Controlling cellular polarity survival proliferation differntiation and fate
  4. Inhibitng or facilitating cell migration
  5. Binding to and acting as a reservoir of growth factors
  6. Activating cell surface signaling receptors
78
Q

What are ECM protiens

A

Hydrophilic Proteoglycans (which absorbs water and tissue resilency) structural adhesive and special cell surface protiens

79
Q

What does alpha 1 beta 1 bind to

A

collagen

80
Q

What does alpha 5 and Beta one bind to

A

fibronectin

81
Q

What does alpha 6 and beta 1 bind to

A

laminin

82
Q

What is a heterodimer

A

Many alpha and beta combination

83
Q

What makes focal adhesions

A

When fibronectin binds to the intergins

84
Q

Can a cell be migartory and non migartory

A

NO it can not bind to make stress fibers and focahal adhesions and lamina and kertain at the same time

85
Q

What does a cell migrating need

A

Fibronectin needs alpha 5 beta one is lamepodiulia locking to bring intergrins when binds it will form a fochal adhesion and stress fiber for cell migration

86
Q

What happens when an integrin is bent

A

Can not bind to ECM

87
Q

When can intergrin be active

A

Partially active when when one is extended and closed fully active when it is extended and open

88
Q

What do intergrins do

A

Promote molecules in cell migration

89
Q

What do selectins recognize

A

Oligosachaccarides

90
Q

What are the steps of leukocyte extravasation

A
  1. Leukocyte is in resting state
    Alpha L beta 2 intergrin attached
    And selecting ligand which are specefic carbohydrated
    PAF receptor
    On the molecule you have ICAM
    This is to the endothelial cell which lines bloods vessels and regulates exchange between the bloodstream and surrounding tissues
    Vesicle containg P-selectin
    Resting state when there is no bacteria
91
Q

Step 2

A

Endothelial activation and leukocyte attachment and rolling
Usually not bound wants to leave so it rolls around
The bacteria causes release of the P-selectin which binds to the selectin ligand (sugars)

92
Q

Step 3

A

Leukocyte activation
PAF activates intergrin
Starts rolling around finally binds to the pAF receptor binds to PAF
This activates the integrins
It is because once it binds to PAF it activates integrins

93
Q

Step 4

A

Firm adhesion via integrin/ICAM binding
ICAM stops the rolling
The integrigs can bind to ICAM
Cell to cell adhesion

94
Q

Step 5

A

Extravasation
Leukocyte squeezes between endothelial cell as it moves from the blood into the tissue
P selectin is being secreted
In presence of infection you want to secret it
Strong binding pushes it in between

Biology (11 decks)

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