Question

Why do some vesicles return to the ER

ans:Quality Control: Retrograde transport retrieves misfolded or mislocalized proteins for proper processing or degradation.
Maintenance: Maintains ER functionality by correcting errors in protein trafficking.
ER Residents: Some proteins resident in the ER cycle between the ER and the Golgi through retrograde transport.
Lipid Regulation: Contributes to the regulation of lipid composition in the ER.
Overall: Ensures protein quality, ER integrity, and balance of essential components within the endomembrane system.

Answer 1

Vesicles containing proteins and lipids bud from the ER, fuse with the Golgi apparatus where they are processed, and then more vesicles with modified proteins and lipids are formed and transported to their final destinations.

Step-by-step explanation:

Transport vesicles leaving the ER fuse with the Golgi apparatus on its receiving, or cis, face. The proteins are processed within the Golgi apparatus, and then additional transport vesicles containing the modified proteins and lipids pinch off from the Golgi apparatus on its outgoing, or trans, face. These outgoing vesicles move to and fuse with the plasma membrane or the membrane of other organelles.