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

• A. An amide linkage involves the R group of lysine, while a peptide bond is part of the protein backbone.
• B. An amide linkage is weaker than a peptide bond.
• C. An amide linkage is found only in prokaryotic organisms.
• D. An amide linkage is a type of hydrogen bond, while a peptide bond is a covalent bond.

Answer: (A)