• Question: Can you explain what dna is

    Asked by 256thuc32 to Liad, Claire, Ruth, Ryan, Mako on 19 Jun 2015. This question was also asked by 385thuc32, Jatan123, Legendary Marcin.
    • Photo: Claire Bryer

      Claire Bryer answered on 19 Jun 2015:

      DNA is a chemical that is found in the nucleus of your cells. DNA is written in a code (or sequence) that is the instructions that tell the cell how to work. The four basic chemicals DNA is made from are called nucleotides. The 4 nucleotides are called thymine, guanine, cytosine and adenine. When we write the code we shorten the chemicals to their first letters, so T, G, C and A. So one person might have the code CCCTGTA and another might have CCCAGTA at the same place. Do you see the nucleotide change?
      DNA is made up of 2 strands of these letters that pair up. A always pairs with T and C always pairs with G. If you look at the sequence below you can imagine hydrogen bonds between the separate lines joining the pairs!
      C C C T G T A
      G G G A C A T

      When a long string of nucleotides are paired like these they form a double helix. (see here: )

      DNA works as a code (via a similar molecule called RNA, which changes the T to a U) to tell a special enzyme to make proteins by joining up different amino acids depending on the code. The proteins are then the things that carry out all the functions in the cell.

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