Peptides are chemical compounds that contain two or more amino acids that are collectively referred to as ‘Amino acid polymers’ and joined together by a peptide bond. The peptide bond is a special linkage that binds the nitrogen atom of a single amino acid atom to the carboxyl carbon of another.

The peptides are versed and they are normally classified according to the number of amino acids that constitute the peptide. Oligopeptides are made-up of 10 or few amino acids, whereas, the molecules that have between 10 to 50 counts of amino acids are commonly referred to as the peptides. Any molecule that registers over 50 counts of amino acids is termed as a protein.

The molecules that have a molecular weight that range from thousands to millions are called the polypeptides. A polypeptide is still a protein as it registers more than 50 amino acids, hence the two terms can be used interchangeably.

Peptides have vast array of applications in both biotechnology and medicine. They are also known to regulate different physiological processes. They act as growth factors in some sites, neuron-transmitter in others or endocrine if not paracrine signals in other sites.

In the year 1920, insulin was introduced as the first therapeutic protein to treat the insulin dependent diabetes. The drug was approved by the six FDA agent and released to the market. Apparently, there are over 140 peptides drugs in the clinical trials and about 500 of the peptide drugs in the pre-clinical developments.

Peptides are also used in the diagnosis of different health conditions in the medical field. These includes the C-peptide, that is normally used to monitor the insulin level together with determining the cause of hypoglycemia (low blood sugar).

Peptides can be synthesized by joining the carboxyl carbon of one amino acid to the N-terminus of another. The synthesis process involves two strategies that include the solid phase peptide synthesis and the liquid phase peptide synthesis.