Golgi Complex And Vesicle Transport Flashcards
What are the first and second steps to exiting the ER
- The membrane bound vesicles with cargo inside (protiens) bud from the ER
- The now transport vesicles fuse with each other to make bigger vesicles called vesicular tubular carriers (VTCs) in the ERGIC region
What is the ERGIC region
The endoplasmic reticulum golgi intermediate complex
It’s between the ER and the golgi
What makes up the golgi
It’s made up of cisternae (flat pancakes) stacked up
Closest to ER is the cis face of the golgi then medial then trans face (furthest)
What is the trans golgi network (TGN)
A network of tubules and vesicles
It’s where the protiens get segregated into diff types of vesicles that either head to the plasma membrane or other places
What is the cis golgi network (CGN)
A network of tubules that are interconnected
It’s the sorting station where it determines if protiens need to be returned to the ER or if they need to keep moving through the golgi (to other places like lysosome)
How does protien modification happen in the golgi complex
Give an example
The protiens leaving the ER are sequentially modified
Example: the modification of n linked carbohydrate chains from the ER
The order that the sugars are added depends on where the glycosyltransferases are in the membrane of the golgi
The o linked carbs are entirely made in the golgi (not made from ER)
Glycosylation in the golgi is _____
Varied
What is the first proposed model of how materials move through the golgi
The vesicular transport model
The cisternae stay as 1 stable unit and don’t move
The vesicles bud from one of these compartment and fuse with the next
What is evidence for the first proposed model of how materials move through the golgi
The cisternae has diff enzymes (suggesting it’s separate and doesn’t increase with other cisternae)
Lots of vesicles bud from the edges of the cisternae
What is the 2nd proposed model of how materials move through the golgi
The cisternal maturation model
The cisternae form at the cis face but instead of staying in one spot they take the cargo and Mature into the trans face as they move up
The escaped protiens from ER are brought backward from the top back to the ER
What is the evidence for the 2nd proposed model of how materials move through the golgi
If drugs that block vesicle formation at the ER are introduced, the golgi disappears
Large cargo (collagen) move from the cis golgi to trans without ever being seen in vesicles, suggesting they’re in a cisternae compartment
What model is most like for how materials move through the golgi
The cisternal maturation model
What is anterograde
Materials moving/transported forward from cis to trans
The whole compartment moves and matures
What is retrograde
Transport backward from the trans to cis
Transports the resident golgi and Er enzymes in vesicles
