Candy DNA
| Biology: | Parts of the DNA |
| Grade Range: | Elementary School, Middle School |
| Format: | Hands-on |
This is a common demonstration at science fairs and science nights, and it is an easy way to show students how DNA is shaped and what it is composed of.
Materials
- Rope Candy, such as Twizzlers
- Gummies or Colored Mini Marshmallows
- Toothpicks
- Plates
Safety Precautions
Please read the General Safety section of the Demonstration Safety page before performing this demonstration.
Demonstration
Preparation: sort the gummy candies by color, and label four color groups as A, C, G and T.
- Provide each student with the following:
- Two of the rope candies
- Twelve of the gummy/marshmallow candies (Three from each color group)
- Six of the toothpicks
- Ask the students to build a DNA strand by matching the A-T and C-G candies on toothpicks, and arranging them as they like between the two rope candies. After they finish arranging them, make sure they remember to give their strand a twist, so it has the familiar double helix shape!
Why This Works
DNA, or DeoxyriboNucleic Acid, is what contains the instructions on how a living organism is built. Everything about you, from the color of your eyes to the length of your toes, is coded in your DNA! There are four main molecules in our DNA: Adenine, Cytosine, Guanine and Thymine. These molecules form what we call Base Pairs, where only Adenine and Thymine will match with each other (A-T) and Cytosine and Guanine will only pair with each other as well (C-G). By arranging the pattern of base pairs in different ways, our DNA can create a coded message on how certain parts of our bodies form, develop and grow. The outside walls of our DNA don't stay straight, looking like a ladder. Instead, because our DNA is so long, it coils up, and takes on a double helix shape to better fit inside the cells.
Additional Information
- Be sure to use candies that are not too hard, otherwise the toothpicks might break when the kids try to push them through.