DNA -- the secret code!

Since last class was focused on genetics, I decided this week's class would be about the secret code in genetics -- DNA!  DNA is the blueprint for an organism.  My DNA contains the instructions for making a complete copy of me, and there is one blueprint inside each of my billions of cells (with a few exceptions).  We talked about how exactly cells use their blueprints, using students in the class.

Aaron was the DNA in the cell, so he was located in the nucleus and is the information that is needed to make proteins.  Jakob was the RNA, specifically the messenger RNA, or mRNA, and he is a transcription of the message for a protein.  Inside the nucleus, the DNA gets copied carefully into RNA, which then travels to the ribosome to be translated.  In the ribosome, the RNA, which was Jakob gets made into the protein that is needed, which was Jaedan.  This is called the central dogma (that DNA is transcribed into RNA, which is then translated into protein).

Our games this week focused on the codes that are used for this.  DNA is a code that is made of only four different bases.  We name them using four letters -- A, C, G, and T.  In the first game, DNA workshop, we saw that the structure of DNA is a double helix, and for replicating DNA, first the DNA is unzipped, then the complementary (matching) bases get added on until there are two strands of DNA instead of one. There is a pattern for matching -- A always matches with T and C always matches with G.  For the "Protein Synthesis" part of the game, we saw that first the DNA is unzipped and RNA is made.  RNA uses the same bases as DNA except that instead of T, there is a U.  From the RNA, proteins are made, which are chains of amino acids.  For every three RNA bases, it specifies one amino acid.

We then played the Nobel Prize DNA game, which also had us matching up the base pairs of a DNA double helix.  From this game, we also learned about how much DNA various organisms have.  Humans have 23 pairs of chromosomes, a total of 46 chromosomes, and about 3 billion bases that are a secret code for about 34,000 genes.  Mice have about 22,000 genes, and about 80% of our genes have a matching mouse gene.  We're really not that different from mice, which is why we study them so much!  Students also seemed surprised to learn that yeast is a living organism, and it has plenty of DNA too -- 16 chromosomes.  Two organisms we talked about were the malaria mosquito and the malaria parasite.  The parasite lives in the blood of people who have malaria, and when mosquitoes bite them, they get the parasite and then pass it on to the next person they bite.  This is how malaria spreads.

Lastly, we played the Ribosome Game, in which we take the RNA code, which was copied from the DNA code, and make it into proteins.  You have to remember that A goes with U (in RNA) and C goes with G.  Then we group them into sets of three and find out what amino acids are represented by the code.  We made a short polypeptide chain.