Brainscape's Knowledge GenomeTM

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


See full index

M1 > Cytoskeleton > Flashcards

Cytoskeleton Flashcards

1
Q

Due to Abnormal Ciliary Dynein

  • Symptoms include:
    • Respiratory system abnormalities
    • Situs Inversus
      • Thoracic& abdominal organs on the wrong side of the body.
A

Kartagener’s Syndrome

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

Cell interior composed of:

A
  • Cytoskeleton
  • Cytosol
  • Organelles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cytosol often comprises more than ______% of a cell’s volume.

Site of ______

A

50%; protein synthesis

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

Elements of the Cytoskeleton

A
  • Microfilaments (Actin, “thin filaments”) (6 types)
  • Microtubules (Tubulin) (12 types)
  • Intermediate filaments (31 types)
  • Motor proteins. i.e. Myosins, Dynein, Kinesin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The most abundant protein in most eukaryotic cells

A

Microfilaments

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

Main component of microfilaments, which are double-stranded, thin, and flexible structures

A

Actin

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

Most actin molecules work together to give support and structure to the plasma membrane and are found

A

near the cell membrane

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

Microfilaments are composed _________ , and generate force by ________, causing movement of the intervening strand.

A

of linear polymers of actin subunits; elongation at one end of the filament coupled with shrinkage at the other

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

Actin structures are controlled by the

A

Rho family of small GTP - binding protein:

  • Rho itself for contractile acto-myosin filaments (“stress fibers”)
  • Rac for lamellipodia
  • Cdc42 for filopodia.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Microvilli contain

A

actin

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

Microvilli

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

Microtubules

A
  • Long, hollow, cylindrical structures composed of tubulin and organized around a centrosome, an organelle usually found in the center of the cell near the cell nucleus.
    • One end of each microtubule is embedded in the centrosome; the microtubule grows outward from there.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Microtubules are much more rigid than _______ molecules and have a larger diameter: _______ nanometers

They are _________ and go through a process of continuous growth and decay.

A

actin molecules; 25 nanometers

relatively unstable

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

Microtubules play key roles in:

A
  • intracellular transport (associated with dyneins and kinesins, they transport organells like mitochondria or vesicles)
  • the axoneme of cilia and flagella
  • the mitotic spindle
  • syntheis of the cell wall in plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Molecules that bind to microtubules

A
  1. Colchicine (depresses MT assembly) (avidly taken up by neutrophils, which become suppressed as a treatment for gout)
  2. Tau (abnormal in Alzheimer’s disease)
  3. Motor proteins
    1. Dynein (moves to minus end, center)
    2. Kinesin (moves to plus end, outer)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Moves towards minus end (center)

A

Dynein

19
Q

Kinesin moves towards ______ end (outer)

A

plus

20
Q

Distribution of Cytoplasmic MT’s goes from ______ end to ______ ends

A

Minus ends (internal) to plus ends (outward)

21
Q

Ciliated epithelium contains

A

microtubulues

22
Q

Microtubules in cilia and flagella

A

Axoneme

23
Q

The Axonenme structure

A

(9 doubletes + 2 MT’s)

24
Q

Kartagener’s Syndrome

A
  • Due to abnormal Cilary Dynein
  • Symptoms
    • Respiratory system abnormalities
    • Situs Inversus
    • Thoracic & abdominal organs are on the wrong side of the body
  • Reason: Ciliary moverment aids organogenesis in the early embryo
25
Q

Primary (sensory) cilia are found in many cells:

A
  • Neurons
  • Chondrocytes
  • kidney epithelium, etc.)

Receptors for neurotransmitters and many other molecules localize to cilia

26
Q

Disruption of the sensory functions of cilia is found in a genetic disorder,

A

Bardet-Biedl syndrome

27
Q

CNS Neurons commonly have how many cilia?

A

a single cilium

28
Q

_____ centrioles make a centrosome

A

2 centrioles make a centrosome

Triplet of microtubules

29
Q

Microtubules attach to chromosomes _______

A

kinetochores

30
Q

Rope-like and fibrous, with a diameter of approximately 10 nanometers

A

Intermediate filaments

These filaments extend through the cytosol and help to resist stress and increase cellular stability.

31
Q

Intermediate filaments that form a network surrounding the nucleus

A

nuclear lamina

32
Q

Intermediate filaments maintain cell-shape by

A

bearing tension (microtubules, by contrast, resist compression)

micro and intermediate filaments- cables

microtubules - cellular support beams.

33
Q

Intermediate filaments organize the internal tridimensional structure of the cell by:

A
  • anchoring organelles
  • serving as structural components of the nuclear lamina and sarcomeres

Participate in some cell-cell and cell-matrix junctions

34
Q

Different intermediate filaments are:

A
  • Keratins: in epithelial cells
  • Desmin: in muscle cells
  • Vimentin: in connective tissue cells
  • Neurofilaments: in nerve cells
  • GFAP: Glial Fibrillary Acidic Protein of Astrocytes
  • Lamins: in all cell types: govern shape of nucleus and interconnects nuclear pores
35
Q

Myosin

A
  • A family of ATP-dependent motor proteins involved in muscle contraction and in a wide range of motility processes.
  • Responsible for actin-based motility.

A large number of genes have been discovered.

36
Q

Myosin was originally thought to be restricted to muscle cells (hence, “myo”), but there is no single “myosin” but rather a huge superfamily of genes whose protein products share the basic properties of:

A
  • Actin binding
  • ATP hydrolysis (ATPase enzyme activity)
  • Force transduction
37
Q

Virtually all eukaryotic cells contain myosin isoforms. Some isoforms have _________, while other isoforms are ______.

A

specialized functions in certain cell types (such as muscle); ubiquitous

38
Q

Myosin structure

A
  • Head domain
  • Neck domain
  • Tail domain
39
Q

Domain that binds actin, and uses ATP hydrolysis to generate force and to “walk” along the filament towards the barbed (+) end

  • (with the exception of myosin VI, which moves towards the pointed (-) end).
A

Head domain

40
Q

Domain that acts as a linker and as a lever arm for transducing force generated by the catalytic motor domain. Also serve as a binding site for myosin light chain which are distinct proteins that form part of a macromolecular complex and have regulatory functions.

A

Neck domain

41
Q
A

Myosin I

42
Q
A

Myosin II

43
Q
A
44
Q

Myosin, Actin, & Cell Movement

A

M1 (48 decks)

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