AP BIOLOGY

Detailed explanation-1: -It is responsible for packing proteins from the rough endoplasmic reticulum into membrane-bound vesicles (tiny compartments of lipid bilayer that store molecules) which then translocate to the cell membrane.

Detailed explanation-2: -In all eukaryotic cells, the endoplasmic reticulum (ER) is an intracellular organelle where folding and assembly occurs for proteins destined to the extracellular space, plasma membrane, and the exo/endocytic compartments (Kaufman 1999).

Detailed explanation-3: -The endoplasmic reticulum (ER) uses an elaborate surveillance system called the ER quality control (ERQC) system. The ERQC facilitates folding and modification of secretory and membrane proteins and eliminates terminally misfolded polypeptides through ER-associated degradation (ERAD) or autophagic degradation.

Detailed explanation-4: -Proteins that are destined for export to intracellular membranes or secretion into the plasma are translocated into the ER, where folding takes place prior to secretion through the Golgi apparatus. The ER contains a number of molecular chaperones and folding catalysts that promote efficient folding.

Detailed explanation-5: -The endoplasmic reticulum (ER) is a major protein folding compartment for secreted, plasma membrane and organelle proteins. Each of these newly-synthesized polypeptides folds in a deterministic process, affected by the unique conditions that exist in the ER.