The answer is:
Peptide bond
Here is more about it:
A peptide bond is a covalent bond between two amino acids. They are linked together through the bond between their carboxyl group. It is also known as an amide bond.
The structure of an amino acid is basically a central carbon atom linked to an amide group and a carboxyl group, which is also linked to a hydrogen atom. When the carboxyl group connects with another amino acid's carboxyl group water is released and this is called a dehydration reaction .