Describe how the sequence of bases in a DNA molecule would be used to form the primary structure of a protein.

The sequences of bases in a DNA molecule will determine the amino acid sequence in the protein that it encodes for. The bases are arranged in triplets where one triplet will encode for one amino acid in a non-overlapping fashion. The DNA must be unzipped to allow for transcription to take place where complementary mRNA molecules line up on next to the template strand of DNA. These moleucles are then joined by RNA polymerase and once a stop codon is reached, the mRNA synthesis will stop and the mRNA molecule will be transported out of the nucleus via a nuclear pore into the cytoplasm where translation can take place. The mRNA is loaded into a ribosome with three triplets being loaded at any one time. A tRNA molecule attached to an amino acid will then enter the ribosome and if the tRNA molecule has an anticodon that is complementary to the mRNA codon then the amino acid will be joined by a peptide bond to the amino acid attached to the next complementary tRNA molecule by a peptide bond. Once the whole mRNA molecule has been translated then a polypeptide chain of amino acids is formed and thus it has a primary structure which can go on to be modified by other molecules.