MSOE > CBM > Student Programs > Science Olympiad > The Molecular Story of XIAP > DNA Sequencing

DNA in the Cell

DNA (DeoxyriboNucleic Acid) contains the blueprints or instructions for how to properly construct proteins. Or more specifically, DNA encodes – in its sequence of nucleotides – the sequence of amino acids that should be joined together to make proteins. Proteins, such as the XIAP protein that is the focus of the 2012 Science Olympiad Protein Modeling Event, are responsible for performing countless jobs in our cells. They act as small molecular machines, each with a unique shape and a unique job to perform.

The human genome is composed of 3.2 billion basepairs of DNA. This genome is divided into 23 chromosomes, found in the nucleus of every cell in your body. To keep these long linear polymers of DNA from getting all tangled up, the DNA of each chromosome is packaged into repeating structural subunits called nucleosomes (~200 basepairs per nucleosome). DNA exists as a double–stranded structure with two twisting backbones and four different bases: adenosine, thymine, guanine, and cytosine.

DNA is in the nucleous of the cell

There are many ways to graphically represent DNA. Three such representations are shown above, including DNA as a 3–dimensional structure, a 2–dimensional graphic, and a simple sequence of letters. Click on the buttons above to explore DNA structure in more detail.

(Note that the 3–dimensional display can be rotated by clicking and dragging.)