Tissue Architecture Flashcards
Cytoskeletal function on the tissue level
- muscle movement
- muscle contraction
Cytoskeletal function on the cellular level
- cell morphology
- cell shape
- motility
- cell adhesion
- cell division
Cytoskeletal function on the subcellular level
- organization
- tensile strength
- chromosome segregation
- cell polarity
- vesticular movement
Cytoskeletal filaments are ______ and ______
Dynamic and adaptable
* can be broken down by a signal and reassembled at new sites
Thermal Stability of cytoskeletal filaments is derived from what characteristic
Filaments do not exist as a single filament but instead exist has thermally stable multi filament complex
Staggered long subunits give rise to a _____ characteristic of cytoskeletal filaments that give it its strong nature
Rope like properties
*allow it to stretch and bend
*intermediate filaments are resistant to stretching forces
What are the three main types of cytoskeletal filaments ?
- intermediate filaments
- Microtubules
- Microfilaments
Microfilaments are made up of
Actin
Microtubules are made up of
Tubulins
Intermediate filaments are made up of
Lamin and cell specific proteins
What is the function of intermediate filaments ?
Increase the tensile strength of cytoskeleton from rope like properties
-enable cells to withstand mechanical stress
Where are intermediate filaments found ?
In the cytoplasm of most animal cells
*surround the nucleus and extend into periphery
Often anchored to plasma membrane and cell-cell junctions
Intermediate filaments form mesh-like structure called the _____
Nuclear lamina
*strengthens nuclear envelope
Describe the route in which an intermediate filament grows
Alpha helical monomer -> coiled-coil dimer -> staggered tetramer of 2 coiled-coil dimers -> lateral association of 8 tetramers —> addition of 8 tetramers to growing filament ends
What are the two main, broad types of intermediate filaments
Cytoplasmic and nuclear
What are examples of cytoplasmic intermediate filaments
- Keratin filaments (in epithelial cells)
- Vimentin and vimentin-related filaments (in CT, muscle, and glial cells)
- Neurofilaments (in nerve cells)
What is the one type of nuclear intermediate filament
Nuclear Lamins
In all animal cells
What disease can be caused if there is destruction to the nuclear lamina that protects the cell
Progeria (accelerated aging)
What is the difference between nuclear lamin and lamina
Nuclear lamins, also known as Class V intermediate filaments, are fibrous proteins providing structural function and transcriptional regulation in the cell nucleus. Nuclear LAMINS interact with membrane-associated proteins to form the nuclear LAMINA on the interior of the nuclear envelope.
What is the function of microtubules?
*crucial eukaryotic cell organization
- forms mitotic spindle for chromosome segregation in mitosis
- part of cilia/flagella
- extends from centrosome to cell periphery to transport cellular components (in non-dividing cells)
Long and stiff, hollow tubes that can be rapidly assembled and disassembled refer to which cytoskeletal filament
Microtubules
A tubulin heterodimer unit is made up of what two subunits? And a tubulin heterodimer is a subunit for what structure ?
Alpha-tubulin and beta-tubulin
A protofilament
Which is a subunit for a microtubule
A microtubule had a plus end a minus end. Which side grows faster?
The plus end grows faster, the minus end grows slower
What is the role of gamma-tubulin in the nucleation of microtubules at the minus end
Gamma-tubulin is the anchor point of the minus end from which the plus end can grow in the opposite direction.
-nucleating sites have gamma-tubulin ring complexes surrounding a pair of centrioles in which microtubules grow at their plus ends
