A yummy DNA Demonstration! Candy Replication Cells contain genetic information called DNA. Before a cell can divide and help an organism grow, repair, or reproduce, it must replicate its DNA so that the new cell has a copy! Today, we are going to model this using Skittles and Twizzlers. A yummy DNA Demonstration!

Paper and writing utensil Step 1: Paper and writing utensil All info needs to be in your notebook on page 56, so grab your notebook and a writing utensil and move to a lab station. You will be working with your shoulder partner to model the DNA replication, but each of you needs your own notebook.

Naming your nucleic acids Step 2: Naming your nucleic acids Take the Skittles out of the cup. Group them by color (you should have at least 4 of each) On your paper, make a key that tells which color stands for which of DNA’s nucleic acids. Below is an example: Blue = Adenine Green=Thymine Orange = Cytosine Red=Guanine

Step 3: Set up Your String Take your Twizzler and pull off four string-like pieces. Set two of them to the side. Using the other two, make two parallel lines, like this:

Step 4: Match your Acids Remember, your nucleic acids will only match with one partner. Let’s test your memory: Adenine matches with… Cytosine matches with… Put 3 pairs (any three you’d like!) in between your parallel Twizzlers. Your finished product should look like this: Thymine Guanine

Step 5: Check Your DNA C G A T Make sure that your adenines are only matched up with thynines, and that your cytosines are only matched up with you guanines. When you think you have it perfect, raise your hand! On your paper, draw your DNA as it looks write now and label it “STEP ONE.” Label your nucleic acids A, T, C, and G – like this!

During interphase, the DNA strand divides in half During interphase, the DNA strand divides in half. So, basically it goes from looking like this… To looking like this…kinda like it unzipped! A T C G A T C G

Step 6: Unzip your dna strand Go ahead and pull apart your two strings, taking half of the nucleic acids (M&M’s) with each piece of string. Draw a picture and label this “STEP TWO” A T C G

Draw and label this “STEP THREE” Time for new string Now take the two remaining pieces of Twizzler and lay them parallel to each unzipped DNA piece. I’ve highlighted these new strings red for you to see the difference. A C T T G A Draw and label this “STEP THREE”

Draw and label this “STEP FOUR” Match Up Your Acids Finally, add your remaining M&M’s to make a brand new and complete DNA strand! You should have 2 identical strands when you are finished! A C T T G A A C T T G A Draw and label this “STEP FOUR”

And that’s Candy Replication! Step 9: EAT SOME YUMMY DNA As you are eating, write a short description of what happened at each of the four steps to help you remember! A C T T G A A C T T G A And that’s Candy Replication!