Final answer:
N-linked glycosylation occurs on asparagine (Asn) amino acids, while O-linked glycosylation occurs on serine (Ser) or threonine (Thr) amino acids.
Step-by-step explanation:
In proteins, N-linked glycosylation occurs when a carbohydrate chain is attached to the amino acid asparagine (Asn). These carbohydrate chains are added to the protein in the rough endoplasmic reticulum (RER) and further modified in the Golgi apparatus. Only certain Asn residues in a specific protein sequence can undergo N-linked glycosylation.
O-linked glycosylation, on the other hand, involves the attachment of carbohydrate chains to the amino acids serine (Ser) or threonine (Thr). O-linked glycosylation occurs in the Golgi apparatus and can occur on any Ser or Thr residue in a protein sequence.