2.1.5- Other Features Of Eukaryotic Cells Flashcards
What are ribosomes made of?
Ribosomal RNA.
Where are ribosomes made?
Nucleolus.
Explain how ribosomes are made.
They’re made in the nucleolus as two separate subunits and pass through the nuclear envelope to the cell cytoplasm which is where they combine.
After ribosomes are made, what are the two places they can go to within the cell?
They can either remain free in the cytoplasm or attach to the rough endoplasmic reticulum (RER).
In eukaryotes, ribosomes are _______ and _______ organelles.
small and spherical.
In eukaryotic cells, what size are the ribosomes?
About 20nm in diameter.
What is the function of ribosomes that are bound to the exterior of the rough endoplasmic reticulum?
They synthesise proteins that will be exported out of the cell.
What’s the function of ribosomes free in the cell cytoplasm?
They assemble proteins that will be used inside the cell.
What are the two ways ribosomes free in the cell cytoplasm can exist?
Singular or in clusters of ribosomes.
What are the four non membrane bound organelles that are going in a eukaryotic cell?
Ribosomes
centrioles
Cytoskeleton
Cellulose cell wall
Explain what the structure of centrioles is.
They consist of two bundles of microtubules at right angles to each other. The microtubules are made of tubulin protein subunits that are arranged to form a cylinder.
The microtubules in centrioles and the cytoskeleton are made of…
Tubulin subunits.
What are the two main functions of centrioles?
- involved in cell division.
* involved in the formation of cilia and undulipodia.
Explain how centrioles are involved in cell division.
Before cell division, the spindle (made of tubulin threads) forms from centrioles and chromosomes attach to the middle part of the spindle and motor proteins walk along the tubulin threads to pull the chromosomes to opposite ends of the cell.
Explain how centrioles are involved in the formation of cilia and undulipodia.
Before the cilia form, the centrioles line up and multiple underneath the cell surface membrane. The microtubules sprout outwards from each centrioles to form a cillium or undulipodium.