The plasmalemma is known by which other name?
Many proteins are anchored into the cell membrane, what functions may they have?
What are the three types of filaments that make up the cytoskeleton of a cell?
- Intermediate filaments
What are the smallest type of filaments that make up the cytoskeleton?
(approx 7nm diameter)
Microfilaments are composed of what?
There are more than 50 classes of intermediate filaments, what can each class give an indication of?
Origin of the cell in the body
(this can help when locating tumours)
What are microtubules composed of?
Alpha and beta tubulin subunits
Which two proteins can use microtubules as a transport network and which direction does each travel?
- Kinesin - An ATPase that transports compounds towards the cell periphery
- Dynein - An ATPase that transports compounds towards the cell centre
The nucleus is surrounded by an _______ and ________ membrane
Inner and outer
The outer membrane of the nucleus shares a common border with what?
The rough endoplasmic reticulum
What is between the inner and outer nuclear membranes?
There are three types of RNA, which two are transcribed and which is transcribed in the nucleolus
Nucleus - mRNA, tRNA
Nucleolus - rRNA
The nucleus contains two states of DNA, what are these states?
- Heterochromatin - DNA condensed and not undergoing transcription
- Euchromatin - DNA untwisted and undergoing transcription
Where are ribosomes formed?
What two subunits make up a ribosome?
- Small subunit - binds to mRNA
- Large subunit - catalyses formation of peptide bonds
What are the two types of endoplasmic reticulum?
What are polysomes?
Clusters of free ribosomes in the cytoplasm surrounding mRNA which is being transcribed
What is the role of the smooth endoplasmic reticulum?
Processing proteins after passage through the rough endoplasmic reticulum and also for the synthesis of lipids
What is the role of the rough endoplasmic reticulum?
The synthesis of membrane bound proteins or secretions.
It is also the site of glycoprotein formation
What is the role of the golgi apparatus?
The pakaging and processing of proteins for export to their destinations
The golgi apparatus is made up of many flattened sacs resembling plates, what is each sac called?
How do proteins arrive at the golgi apparatus?
In transport vesicles from the smooth endoplasmic reticulum
What is the inner membrane of mitochondria called?
This is folded to increase surface area
DNA can be found in which two locations within a cell?
- Mitochondria - they have their own DNA
Which type of muscle will have many mitochondria and which type will have few?
- Many mitochondria - Slow twitch muscle - generally aerobic
- Few mitochondria - fast twitch muscle - generally anaerobic
What are intercellular junctions?
Structures specilaised to join cells into groups to form a functional unit
Where are intercellular junctions most prominent?
What are the three types of intercellular junctions?
Occluding junctions can have which other name?
(or zonula occludens)
What do occluding junctions function to do?
Link cells together to form a diffusion barrier