<P> The primary structure of a protein refers to 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 . 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 ( NH - 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 . The sequence of amino acids in insulin was discovered by Frederick Sanger , establishing that proteins have defining amino acid sequences . The sequence of a protein is unique to that protein , and defines the structure and function of the protein . The sequence of a protein can be determined by methods such as Edman degradation or tandem mass spectrometry . Often , however , it is read directly from the sequence of the gene using the genetic code . It is strictly recommended to use the words `` amino acid residues '' when discussing proteins because when a peptide bond is formed , a water molecule is lost , and therefore proteins are made up of amino acid residues . Post-translational modification such as disulfide bond formation , phosphorylations and glycosylations are usually also considered a part of the primary structure , and can not be read from the gene . For example , insulin is composed of 51 amino acids in 2 chains . One chain has 31 amino acids , and the other has 20 amino acids . </P>
<P> The primary structure of a protein refers to 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 . 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 ( NH - 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 . The sequence of amino acids in insulin was discovered by Frederick Sanger , establishing that proteins have defining amino acid sequences . The sequence of a protein is unique to that protein , and defines the structure and function of the protein . The sequence of a protein can be determined by methods such as Edman degradation or tandem mass spectrometry . Often , however , it is read directly from the sequence of the gene using the genetic code . It is strictly recommended to use the words `` amino acid residues '' when discussing proteins because when a peptide bond is formed , a water molecule is lost , and therefore proteins are made up of amino acid residues . Post-translational modification such as disulfide bond formation , phosphorylations and glycosylations are usually also considered a part of the primary structure , and can not be read from the gene . For example , insulin is composed of 51 amino acids in 2 chains . One chain has 31 amino acids , and the other has 20 amino acids . </P>
how is primary structure of a protein determined
how is primary structure of a protein determined
by the gene corresponding to the protein
by the gene corresponding to the protein