DNA & production of proteins

• The structure of DNA is described as a double-stranded helix. It has two backbones held together by complementary base pairs as shown in the diagram below.

  
• A - T: adenine - thymine

  C - G: cytosine - guanine
• A gene is a section of DNA that codes for ONE protein
• The sequence of bases is very important in DNA, as the sequence of bases in DNA will determine the amino acid sequence in a protein.

  (Amino acids are the subunits of a protein and have to be in a specific sequence to ensure that the protein produced is the correct shape and fully functional.)
• Messenger RNA (mRNA) is a molecule which carries a complimentary copy of the genetic code from the DNA, in the nucleus, to a ribosome, where the protein is assembled from amino acids. This is called protein synthesis

  
• The DNA codes for the order of amino acids which 'fold' to create proteins