Primary structure of protein: The function of a protein

The function of a protein is highly dependent on its 3D structure. The amino acid sequence of a polypeptide chain determines the final 3D structure of the protein. There are four levels of protein structure; the primary structure, the secondary structure, the tertiary structure, and the quaternary structure. A protein’s primary structure is the unique sequence of amino acids in each polypeptide chain that makes up the protein. Because the final protein structure ultimately depends on this sequence, this is called the primary structure of the polypeptide chain. Protein primary structure is the linear sequence of amino acids in a peptide or protein. [1] By convention, the primary structure of a protein is reported starting from the amino -terminal (N) end to the carboxyl -terminal (C) end. To reiterate, the primary structure of a protein is defined as the sequence of amino acids linked together to form a polypeptide chain. Each amino acid is linked to the next amino acid through peptide bonds created during the protein biosynthesis.