How do you make a DNA molecule model?

A popular science fair project for younger children is to create a model of DNA using candy. To make this project, you need red licorice, black licorice, four different types of gummy candies, a needle, thread and toothpicks.

1. Create the licorice chains

   Assign one color of licorice to represent the pentose sugar of the DNA polynucleotide and the other color to represent the phosphate sugar. Cut the licorice into 1-inch long pieces. Thread the needle, and string the licorice pieces on the thread to form a chain, alternating colors. Create a second licorice chain the same way. If the first chain starts with a piece of black licorice, make sure the second chain starts with a piece of red licorice.

2. Sort the gummy candies by color or type

   Divide the gummy candies into four distinct colors or easily recognizable types. Assign each of the four groups to represent the nucleotide bases of adenine, cytosine, guanine and thymine. Match the gummy candy nucleotides with their corresponding partners, pairing adenine and thymine and guanine with cytosine.

3. Attach the gummy candies to the licorice

   Use the toothpicks to spear pairs of gummy candy nucleotide bases and attach them to the licorice strands. Each toothpick should act like the rung of a ladder, connecting across the two licorice strands. Once you have finished, take either end of the candy molecule, and twist the ends in opposite directions to create the double helix look of the DNA molecule.