lecture 5 Flashcards
what does cell motility mean
the abiltity for the cell to move and move its organelles
role of the cytoskeleton
The most obvious function of the cytoskeleton is to support the structure of the cell and maintain its shape. It also maintains the shape and function of the cell, as the cytoskeleton holds the organelles in place within the cell.
why do animal cells have cytoskeleton and plant cells don’t
because the plant cell has structure and support due to its cell wall, the animal cell doesn’t have this so the cytoskeleon instead provides support.
the cytoskeleton is dynamic, what does this mean
it can quickly be dismantled in one place then rebuilt in another area, changing the shape of the cell.
how does the cytoskeleton support motility of organelles
the kinesin walk, motor proteins walk and drag vesicles along microtubule high ways, along the cytoskeleton.
how does the cytoskeleton support vesicle production
The cytoskeleton also indents the plasma membrane to form the exocytosis vacuoles.
what are the three components of cytoskeleton
microtubules, microfilaments and intermediate filaments
describe the structure and the benefits of the microtubule structure
creates high amounts of compression resistance which thus helps to maintain cellular shape. Made of tubulin subnits, 25 nm diameter, these radiate out from organising centre, centrosome,
describe the structure and the benefits of the microfilaments structure
7nm diameter, two interwoven strands of actin(double twisted) . can be a linear strand or many can join together to create a 3d structure. the rope like structure helps the microfilaments to resist tension. actin also works with proteins like myosin in muscle cells to make muscles contract.
describe the structure and the benefits of the intermediate filaments structure
microfilaments are the most permanent component of the cytoskeleton, made of various proteins, keratin in hair, lamins in nucleus, neurofilaments in neurons, Supercoiled into “cables” 9-12 nm diameter. as its so strong its less dynamic, which makes the intermediate filament anchor organelles more permanently.
whats special about flagella and cilia
they are structures of a cell that are made from microtubules
what compensates for the lack of cell wall in an animal cell
the ECM
what is the ECM made of
The main ingredients for this ECM is Glycoproteins and other carbohydrate containing molecules that are secreted by cells. The most abundant glycoprotein in the ECM is collagen, which forms strong fibres outside the cell. Collagen is about 40% of all protein in the body.
what are collagen fibres embedded within
a woven network of proteoglycans.
whats special about the network of proteoglycans
These proteoglycans are secreted by cells and consist of core proteins with many carbohydrate chains attached to it.
Proteoglycan complexes form when hundreds of proteoglycans are attached together. Cells that are attached to the ECM are attached by glycoproteins, such as fibronectin.
