The primary structure of a protein is the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis. Amino acids are chemically linked together to make long amino acid chains through a condensation reaction (sometimes called dehydration synthesis). The twenty types of amino acids can be joined together in any order or frequency, allowing for an astronomical variety of potential primary structures.
The two ends of the polypeptide chain are referred to as the carboxyl terminus (C-terminus) and the amino terminus (N-terminus) based on the nature of the free group on each extremity. Counting of residues always starts at the N-terminal end (NH2-group), which is the end where the amino group is not involved in a peptide bond. The primary structure of a protein is determined by the gene corresponding to the protein. A specific sequence of nucleotides in DNA is transcribed into mRNA, which is read by the ribosome in a process called translation.
Methods of creating a primary structure of proteins consists of synthesized nucleotide sequence which is encode the necessary protein structure by triplets of genetic code. Also it should include the sequences needed for translation.