The Cytoskeleton Flashcards
what is defined as the cellular scaffolding or skeleton contained with the cytoplasm in all cells?
the cytoskeleton
What are the 5 functions of the cytoskeleton
- it maintains cell shape
- protects the cell
- enables cellular motion (using structures such as flagella and cilia)
- intracellular transport (ie movement of vesicles and organelles)
- cell division
name the three different types of cytoskeleton filaments
- microfilaments (actin)
- intermediate filaments
- microtubules
Where are microfilaments most concentrated in the cell?
just beneath the cell membrane
what are microfilaments comprised of?
two intertwined filamentous actin ( F-Actin) chains
which parts of the cytoskeleton are responsible for resisting tension?
microfilaments
Which aspect of the cytoskeleton is important for cytokinesis
microfilaments
which parts of the cytoskeleton are responsible for maintaining cellular shape
microfilaments
which parts of the cytoskeleton are responsible for participating in some cell to cell or cell to matrix junctions?
microfilaments (F-actin)
Which aspect of the cytoskeleton is important for muscular contraction (with myosin)?
microfilaments
Which aspect of the cytoskeleton is important for cytoplasmic streaming (with myosin)
microfilaments
what diameter are intermediate filaments
8-10 nanometers
Where are intermediate filaments found in the cell?
throughout the cell
Why are intermediate filaments more stable than microfilaments?
they are more strongly bound than actin filaments
what is vimetin
Vimentin is a structural protein that in humans is encoded by the VIM gene. Its name comes from the Latin vimentum which refers to an array of flexible rods.
what is keratin
one of a family of fibrous structural proteins known as scleroproteins. α-Keratin is a type of keratin found in vertebrates. It is the key structural material making up hair, nails, feathers, horns, claws, hooves, calluses, and the outer layer of skin among vertebrates.
which aspect of the cytoskeleton can be composed of vimetins
intermediate filaments
which aspect of the cytoskeleton can be made of keratin
intermediate filaments
which aspect of the cytoskeleton is found in neural cells
neurofilaments
which aspect of the cytoskeleton is very dynamic in behaviour (constantly elongates and shortens)
microtubules
which aspect of the cytoskeleton is made of alpha and beta tubulin
microtubules
which aspect of the cytoskeleton is able to resist compression compared with other cytoskeletal filaments
microtubules
how wide is the lumen of a mictotubule
15 nanometers
which cytoskeletal filament is arranged in an imperfect helix
microtubule
which cytoskeletal filament is composed of two heterodimers ( a and b tubulin)?
microtubule
which cytoskeletal filament has polarity
microtubule (due to alpha-tubulin at one end and beta-tubulin at the other)
how many tubulin dimers does each turn of the microtubules helix have?
13 tubulin dimers each from a different protofilament
what is a protofilament
A protofilament is a linear row of tubulin dimers
which cytoskeletal filament plays a key role in Intracellular transport (they transport organelles like mitochondria or vesicles)
microtubules
which cytoskeletal filament plays a key role in the cytoskeleton (axoneme) of cilia and flagella
microtubules
which cytoskeletal filament plays a key role in synthesis of the cell wall in plants?
microtubules
which cytoskeletal filament plays a key role in The mitotic spindle?
microtubules
what organelle can microtubules form?
centrioles
how are the microtubules in centrioles arranged?
9 triplet sets
what organelle is involved in the organisation of the mitotic spindle and in the completion of cytokinesis
centrioles
what form cilia and flagella
microtubules
how are the microtubules oriented in cilia or flagella?
9+2 arrangement; Microtubules are in nine doublets oriented about two additional microtubules (wheel-shaped)
Which part of the cytoskeleton thickens the cortex around the inner edge of a cell and resist tension like rubber bands?
microfilaments
Which part of the cytoskeleton are found in the interior of the cell where they maintain cell shape by resisting compressive forces?
microtubules
Which part of the cytoskeleton is found throughout the cell and hold organelles in place.
intermediate filaments
