What is a polypeptide?

A polypeptide is a long, continuous, and unbranched peptide chain of amino acids linked by peptide bonds.

Polypeptides are crucial components in the body, playing a significant role in the structure and function of cells. They are formed by the polymerisation of amino acids, which are the building blocks of proteins. This process involves the formation of peptide bonds, which are covalent bonds that link one amino acid to another.

The sequence of amino acids in a polypeptide chain is determined by the sequence of nucleotides in the DNA that codes for it. This sequence is unique for each polypeptide and determines its specific properties and functions. The polypeptide chain can fold into a specific three-dimensional shape, which is essential for its function.

Polypeptides can function as enzymes, hormones, antibodies, and structural components of cells. For example, the enzyme amylase is a polypeptide that breaks down starch into sugar. Insulin, a hormone that regulates blood sugar levels, is also a polypeptide.

In summary, polypeptides are long chains of amino acids that play a vital role in the structure and function of cells. They are formed by the polymerisation of amino acids, and their sequence is determined by the DNA that codes for them. Their unique sequence and structure enable them to perform a wide range of functions in the body.