Peptide bonds are found in proteins. Proteins are composed of amino acids, and the peptide bonds hold these together in polypeptide chains.
When two amino acids bond together through a peptide bond, the result is called a dipeptide. When a peptide bond is created between two amino acid molecules, a condensation reaction occurs; this refers to a molecule of water being released during the bonding process. The reverse can also occur; this is known as a hydrolysis reaction and refers to a molecule of water being added to an amino acid bond and splitting the original molecule into two.