2.1.5 Other features of eukaryotic cells Flashcards
what shape are ribosomes?
small spherical
what is the diameter of a ribosome?
about 0.02 micrometres
what are ribosomes made of?
ribosomal RNA
where are ribosomes made?
the nucleolus, as two separate subunits, which pass through the nuclear envelope into the the cell cytoplasm and combine
where do ribosomes go?
some remain free in the cytoplasm and some attach to the rER
what is the function of ribosomes bound to the exterior of rER?
mainly synthesis proteins that will be exported out the cell
what is the function of ribosomes that are free in the cytoplasm?
primarily the site of assembly of proteins that will be used inside the cell
what does a centriole consist of? structure
two bundles of microtubules at right angles to each other
what are the microtubules in centrioles made of?
tubulin
what organelle are only found in animal cells?
centrioles and microvilli
what organelle are only found in plant cells?
cellulose cell wall, large permanent vacuole and chloroplasts
what are all cells surrounded by?
a plasma membrane which controls the exchange of materials between the internal cell environment and the external environment (partially permeable)
what is the plasma membrane formed by?
from a phospholipid bilayer of phospholipids
what is the diameter of a plasma membrane?
0.01µm
what connects the cytoplasm to neighbouring plant cells?
narrow threads of cytoplasm (surrounded by a cell membrane) called plasmodesmata connect the cytoplasm of neighbouring plant cells
