DNA stands for deoxyribonucleic acid. It is a long thin molecule made up of things called nucleotides, sometimes referred to as bases. There are four different types of nucleotides: adenine, thymine, cytosine, and guanine. The nucleotides are represented by their first letter: A- adenine T- thymine C - cytosine G - guanine. The nucleotides pair up and are called base pairs. These base pairs form the middle structure of our DNA strand (the parts that look like rungs on a ladder.) Only certain nucleotides can pair together: A only connects with T and G only connects with C. The outside of the structure holds the DNA strand together on both sides while twisting. The shape it makes is called a double helix.
Lets make a double helix out of paper. You can get the file here.
Step 1: Fold Your Page
Cut out the DNA pattern. Turn it so that the colored side faces down and fold it in half along the bold center line.
Step 2: Fold Horizontal Lines
Fold the paper down along the first horizontal line. Crease it well and unfold it. Repeat this for all of the horizontal lines. When you are done your paper will start to curl up in a "c" shape.
Step 3: Fold Diagonally
Now fold along the first diagonal line. Crease well and unfold. Repeat this for all of the diagonal lines. Now your paper will start to curl inwards and twist a bit.
Step 4: Fold Blank White Side
Fold the blank white side towards you. Crease it well.
Step 5: Fold the Next White Side
Flip your paper over and fold the remaining white side upwards. Crease it well. Now slightly unfold each white side so that they stand up at a right angle. One will be pointing towards you, the other towards the table.
Step 6: Gather the Folds
Now gather the folds you've made one at a time in accordion fashion- with the first coming toward you and the next away and so on. Your paper strip will start to twist and layer under itself- you will see triangles of color as each fold layers behind the other. Do this until your entire strip forms a flat circular shape. The white sides will still be sticking up at a right angle to the colored sections.
Step 7: Let It Unfurl
Release the hold you have on the circle and it will unfurl into a twisted shape- a double helix.