Peptide Bond Formation in Translation

Steps:

• Identify amino acids in diagrams: each has N-terminal amino group and C-terminal carboxyl group.
• Recall peptide bond forms via dehydration synthesis, linking C of one amino acid to N of the next.
• Examine diagrams for correct orientation: bond between carboxyl (COO-) and amino (NH2) groups.
• Select diagram showing this linkage without incorrect bonds or structures.

Why A is correct:

• Diagram A depicts the standard peptide bond per the definition: covalent amide linkage (-CO-NH-) between adjacent amino acids' functional groups.

Why the others are wrong:

• B shows bond between two amino groups, violating dehydration synthesis.
• C links two carboxyl groups, forming anhydride instead of peptide bond.
• D illustrates no bond or incorrect side-chain connection, not involving terminal groups.

Final answer: A