Cell membrane, Microvilli, Centrioles Flashcards
The cell membrane is extremely…
thin about 7 nm.
The cell membrane has…
3 layers so it has a trilaminar appearance.
Microvilli are…
finger-like extensions of the cell surface membrane.
Microvilli greatly…
increase the surface area of the cell membrane.
Microtubules are…
long, rigid and hollow tubes found in the cytoplasm.
Microtubules diameter
25 nm.
Microtubules make up…
the cytoskeleton, an essential structural component of cells which helps to determine the shape.
Microtubules are made of…
a protein called tubulin.
Two type of tubulin
- alpha-tubulin
- beta-tubulin
These two types of tubulin combine…
to form dimers(double molecules). These dimers are then joined end to end to form long protofilaments. This is an example of polymerisation.
13 protofilaments line up…
alongside each other in a ring to form a cylinder with a hollow centre. This cylinder is a microtubule.
Other function of microtubules
Secretory vesicles, other organelles and cell components can move along the outside surfaces, forming an intracellular transport system.
Membrane-bound organelles are held in…
place by the cytoskeleton.
During nuclear division, the spindle…
used for the separation of chromatids of chromosomes is made of microtubules and microtubules form a part of the structure of centrioles.
MTOCs
Microtubule organising centres. Where the microtubules are assembled within the cell.
