Make a Candy Model of DNA

1. Find out what an actual DNA strand looks like.
2. Learn how nucleotides are formed.
3. Show replication, splicing, and more functions involving the DNA double helix.

Materials:

  • Licorice sticks or ropes in 2 different colours, 
  • Gumdrops, jelly beans or marshmallows in 4 colours
  • Toothpicks
  • Fishing line or string 
  • Scissors

Now Follow These Steps:

A. Assign names to the 4 different coloured candies to represent nucleotide bases. There should be four different colours each representing either adenine, cytosine, guanine or thymine. 

B. Assign names to the coloured licorice pieces with one colour representing the pentose sugar molecule and the other representing the phosphate molecule.

First: Cut licorice into into small equal size pieces then string half of the licorice pieces together lengthwise alternating between the 2 different colours. Repeat the procedure for the remaining licorice pieces to create a total of two stands of equal length.

Second: Connect two different coloured candies together using the toothpicks. Connect the toothpicks with the candy to the licorice strands so that the candy pieces are between the two strands.

Next: Holding the ends of the licorice sticks, twist the structure slightly and you have a DNA model!

Results and Questions

1. What do the small candies represent? (Bases)

2. What do the toothpicks represent? (Hydrogen bonds holding bases together)

3. What do the licorice pieces represent? (Alternating sugar and phosphate molecules)

Watch A Video of the Experiment