In the context of ubiquitination, how does an amide linkage differ from a peptide bond?

An amide linkage involves the R group of lysine, while a peptide bond is part of the protein backbone.

An amide linkage is weaker than a peptide bond.

An amide linkage is found only in prokaryotic organisms.

An amide linkage is a type of hydrogen bond, while a peptide bond is a covalent bond.