Download DNA candy construction

Name________________________
Date__________________
Block____________
Have Your DNA and Eat It Too!
Introduction:
When isolated from a cell and stretched out, DNA looks like a twisted
ladder. This shape is called a double helix. The sides of the DNA ladder are called the backbone
and the steps (also called rungs) of the ladder are pairs of small chemicals called bases. There
are four types of chemical bases in DNA: Adenine (A), Cytosine (C), Guanine (G), and Thymine
(T). They form pairs in very specifi c ways: Adenine (A) always pairs with Thymine (T) and
Cytosine (C) always pairs with Guanine (G).
Goal: Your task is to use the following materials and procedure to construct an edible model
of DNA. When you are finished, use paperclips and tape to label one of each of the chemical
bases.
Materials:
 2 pieces of licorice
 12 toothpicks
 9 pink marshmallows
 9 yellow gummy bears
 9 green gummy bears
 9 orange gummy bears
 5 paperclips
 Masking Tape or post it
Procedures:
Step 1: Color code the nitrogenous bases. Match one nitrogenous base to one color gummy
bear.
Adenine = __________________________
Guanine = __________________________
Cytosine = __________________________
Thymine = __________________________
Step 2: Choose one of the sequences below to start your
construction:
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 3: Assemble one side of your DNA molecule. A piece of licorice will form the sugar
phosphate backbone and gummy bears will be the nitrogenous bases. Place a gummy bear 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. The gummy bear should correspond with the sequence
you chose above.
Name________________________
Date__________________
Block____________
Step 4: Repeat step 3 with another toothpick and gummy bear until you have a created a half
ladder.
Step 5: Label the backbone. With a marker or pen and a strip of
post-it, label your licorice backbone “DNA- 1” or “DNA-2”
depending on which sequence you used. Wrap the label onto
the left end of the licorice.
Step 6: Create the second strand. Match up the nitrogenous
base pairs. Slide the corresponding gummy bear on to the
toothpick. Continue until all of the tooth picks on your half ladder have to gummies.
Remember that A always pairs with T and C always pairs with G!
Step 7: Complete your DNA model. Attach the other backbone so your
model looks like a ladder.
Step 8: Twist your DNA model. Carefully twist your DNA molecule so
that it looks like a double helix.
Step 9: finish labeling your model. Make flags to label the parts of your
DNA out of paper clips and Post-its. Label one of each of the following:
Adenine, Thymine, Cytosine, Guanine, and Backbone. Make sure your
chemical base pairs are correct!
Step 10: Show your teacher for credit!
Answer the Questions below about DNA and RNA
1. Write out the full name for DNA.
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2. Where in the cell are chromosomes located?
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3. What is the shape of DNA?
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4. What are the rails (sides) of the DNA ladder made of?
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8. What are the "steps" (middle) of the DNA ladder made of?
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Name________________________
Date__________________
Block____________
9. What is the name of the sugar found in DNA?
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10. How do the bases bond together?
‘A’ bonds with _____ ‘G’ bonds with _______
11. DNA is made of repeating units of building blocks called
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12. Write out the full name for RNA.
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13. What is the purpose of RNA?
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14. What main organelle is associated with RNA?
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15. What is the shape of RNA?
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16. What are the sides, or “rails”, of RNA made of?
___________________________________________________________
17. What is the middle, or "steps" of RNA made of?
___________________________________________________________
18. What is the name of the sugar found in RNA?
____________________________________________________________
19. How do the bases bond together?
‘A’ bonds with _____ ‘G’ bonds with _______
20. RNA is made of repeating units of building blocks called
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