Answer:
Water
Step-by-step explanation:
A peptide bond is a type of chemical bond between two molecules when an amino group of one molecule reacts with the carboxyl group of another adjacent molecule.
In this process the carboxyl loses its -OH group, while the amine loses a hydrogen atom (-H), these two free bonds eventually cause a new reaction, uniting the amino acids.
Since the peptide bond involves this dehydration reaction, a water molecule (H₂O) is released at the end.