Final answer:
The core portion of N-linked oligosaccharide in ER is synthesized on a lipid carrier called dolichol phosphate, followed by additional processing in the Golgi apparatus. Option 1 is correct.
Step-by-step explanation:
The synthesis of the core portion of N-linked oligosaccharide in the endoplasmic reticulum (ER) occurs on a lipid carrier called dolichol phosphate. This lipid carrier is located within the membrane of the rough ER, where the initial steps of glycosylation occur. Partial glycans are enzymatically attached to compatible amino acids of a nascent protein, beginning the process of glycoprotein synthesis.
As the protein matures, it is transported to the Golgi apparatus via transport vesicles. In the Golgi, terminal glycosylation occurs, attaching additional sugars to the core glycoside.
The fully synthesized glycoprotein is then sorted, packaged, and tagged for distribution to the correct cellular location. This involves traveling from the cis face of the Golgi, through its lumen, and being released at the trans face to reach its ultimate destination.