lecture 5 - endomembrane system Flashcards
How is the endomembrane system interconnected?
By vesicles which move between the organelles
What are the key organelles of the endomembrane system?
Nuclear envelope, endoplasmic reticulum (smooth and rough), golgi apparatus, vesicles, lysosome, vacuoles, plasma membrane
What is the structure of the endoplasmic reticulum (ER)
A series of flattened sacs, connected by tubules, and divided into two regions (smooth and rough).
What are the spaces within the ER?
lumen
What are the key functions of the smooth ER?
Metabolises carbohydrates, synthesise lipids for membranes, detoxificate toxins, store calcium ions.
Is the amount of sER in a cell fixed?
No - it can change to fit cell function requirements.
Does the sER contain ribosomes?
No
Why does the rER have a rough appearance?
It has ribosomes.
What is the function of ribosomes?
They synthesise proteins in the rER
Where are proteins processed in the rER?
In the lumen
Where does synthesis of cytoplasmic proteins occur?
The free ribosomes
How do proteins leave the ER?
In vesicles that ‘bud off’ the surface of the ER.
What is the main function of the golgi?
Receive, sort and distribute proteins from the rER.
What are the two faces of the golgi?
Cis and trans face
What part of the golgi do vesicles arrive at?
The cis face
Where do processed vesicles leave the golgi?
The trans face