Cell Functions and Structures
What is the fluid portion of the cytoplasm around the organelles called?
Cytosol
What is the difference between eukaryotic and prokaryotic cytoplasm?
Eukaryotic cytoplasm includes small fibres and rods called a cytoskeleton while prokaryotic cells do not have a cytoplasm.
What are the functions of the cytoskeleton?
- Maintaining cell shape
- Anchoring some organelles
- Aiding cellular movements
- Providing a means for some organelles to move within the cell
In the cytoskeleton, what are the main roles of the actin filaments (or microfilaments), intermediate filaments, and microtubules?
- Actin filaments AKA microfilaments function in cell divison and movement, especially involving contractions in muscle cells
- Intermediate filaments are found in most animal cells and reinforce cell shape as well as anchor some organelles
- Microtubules shape and support the cell, they also funcion as movement paths or tracks through the cell for some organelles
What is the endoplasmic reticulum?
An extensive network of tubules or channels that extends most everywhere in the cell. Transports materials througout the internal region of the cell.
What is the difference between the smooth and rough ER?
- Smooth ER has no ribosomes on its exterior surface
- Rough ER has ribosomes on its exterior
What is the function of the rough ER?
The ribosomes on its exterior participate in protein synthesis, so the rough ER engages in protein development and transport.
What is a unique about the structure of ribosomes?
They don't have an exterior membrane
What is the function of ribosomes?
They conduct protein synthesis and are always composed of a type of RNA and protein.
What is the difference between ribosomes in prokaryotic and eukaryotic cells?
The ribosomes in eukaryotic cells are larger and denser. Ribosomes have two subunits; in eukaryotic cells, the subunits together equal 80S while they equal 70S in prokaryotic cells.