Two or more amino acids can be linked together by a dehydration synthesis to form a peptide. The characteristic chemical bond is called a peptide bond.
This picture shows two amino acids joined together by
the carboxyl group of one and the amine group of the second. Notice that
a water molecule is removed in the process.
The
word 'peptide' refers to two or more amino acids joined together by peptide
bonds. Peptides can contain more than two amino acids as in this peptide
composed of four amino acids trptophan, methionine, aspartime and phenylalanine.
Longer chains of amino acids strung together are called polypeptides,
more commonly refered to as proteins. Proteins have a complex three dimentional
structure as shown in these RasMol models.
Insulin:
stick model |
Insulin:
Cartoon model showing the arrangement of amino
acids into sheets and coils in the insulin molecule. |
Protein
from cobra venom stick model.  |
Learn more about proteins and protein structure here!
Revised 1/07//00 pgd