2.1.8 Cytoskeleton Flashcards
what is the cytoskeleton? structure
an extensive network of protein fibres, in the cytoplasm
what are the two main types of protein fibres that make up the cytoskeleton?
microfilaments and microtubules (also intermediate filaments)
what are microfilaments? structure
microfilaments are solid strands that are mostly made of the protein actin.
what are microfilaments? function
these fibres can cause some cell movement and the movement of some organelles within cells by moving against each other
what are microtubules? structure
microtubules are tubular (hollow) strands that are mostly made of the protein tubulin.
what are microtubules? function
organelles and other cell contents are moved along these fibres using ATP to drive this movement
what are the three functions of the cytoskeleton?
-strengthening and support
-intracellular movement
-cellular movement
explain the strengthening and support function
the cytoskeleton provides the cell with mechanical strength, forming a kind of ‘scaffolding’ that helps to maintain the shape of the cell
it also supports the organelles, keeping them in position
explain the intracellular movement function
the cytoskeleton aids transport within cells by forming ‘tracks’ along which organelles can move
examples of this include the movement of vesicles and the movement of chromosomes to opposite ends of a cell during cell division
explain the cellular movement function
the cytoskeleton enables cell movement via cilia and flagella
these structures are both hair-like extensions that protrude from the cell surface and contain microtubules that are responsible for moving them
what is the overall function of the cytoskeleton?
the cytoskeleton provides mechanical strength to cells, aids transport within cells and enables cell movement
what are microfilaments made of?
actin
what are microtubules made of?
tubular
where are microtubules found?
in all eukaryotic cells
how are microtubules made?
made of α and β tubulin combined to form dimers, the dimers are then joined into protofilaments
thirteen protofilaments in a cylinder make a microtubule