Peptide bond formation between two amino acids is best described chemically as:

• A. A condensation (dehydration) reaction that links the carboxyl group of one amino acid to the amino group of the next, releasing water.
• B. A hydrolysis reaction that adds water to two amino acids causing them to join through an ester link between side chains.
• C. A redox reaction in which electrons are transferred between side chains to create a disulfide backbone joining residues head-to-tail.
• D. An isomerization event that rearranges the peptide backbone from L- to D-configuration to form a covalent bond between residues.

Answer: (A)