You will need:
2 pieces of licorice
9 pink marshmallows
9 yellow marshmallows
9 green marshmallows
9 orange marshmallows
- You'll be assigned to a team of 4 students.
Step 1: Choose one of the sequences below.
Sequence 1: T A C G T A T G A A A C or Sequence 2: T G G T T T A G A A T T
Step 2: Assemble one side of your DNA molecule. A piece of licorice will form the backbone and marshmallows will be the chemical bases. Place a marshmallow on the end of a toothpick so that the point of the toothpick goes all the way through. Anchor the toothpick into the licorice backbone. Refer to the table above to choose the correct color marshmallow to represent the chemical bases in your sequence.
Step 3: Label the backbone. With a marker or pen and masking tape, label your licorice backbone “DNA- 1” or “DNA-2” depending on which sequence you used. Write the label on the left end of the licorice.
Step 4: Match the chemical base pairs. Place the color marshmallow for the matching chemical base on the other end of each toothpick. Remember that A always pairs with T and C always pairs with G!
Step 5: Complete your DNA model. Attach the other backbone so your model looks like a ladder.
Step 6: Twist your DNA model. Carefully twist your DNA molecule so that it looks like a double helix.
Step 7: Label your model. Make ﬂags to label the parts of your DNA out of paper clips and tape. Label one of each of the following: Adenine, Thymine, Cytosine, Guanine, and Backbone. Make sure your chemical base pairs are correct!