- The amino acid subunits are linked
covalently by peptide bonds.
-Such bonds are the result of a condensation
reaction between the carboxyl group of one
amino acid and the amino group of another.
- Two joined amino acid units, or residues, are
called a dipeptide.
- A third amino acid can join, to form a
tripeptide.
- Condensation reactions can occur again and
again, forming chains that are typically 50 to
hundreds of amino acids long. These polymer
chains are called polypeptides