Mr. Ardito's Classes
Lab - Visualizing DNA, DNA Replication, Mutations, and Protein Synthesis
Overview
Traits are physical characteristics that are passed from parent to offspring. Traits have different versions called alleles. These alleles are carried on chromosomes, which are made of DNA, on sections called genes. Genes are the recipes for the proteins that control these traits.
In this lab, we will use models made of Twizzlers, marshmallows, and toothpicks to investigate the Structure of DNA, DNA Replication, Mutations, and Protein Synthesis.
The Twizzlers will represent that sugar-phosphate backbone of DNA and RNA, the marshmallows represent the nitrogenous bases, and toothpicks represent the bonds that hold the pieces together.
Part 1: DNA Structure
Using the Twizzlers, marshmallows, and toothpicks, make the DNA segment in the diagram below.
Data
Make a color drawing of this section of DNA in your notebooks. Be sure to make a color key for the nitrogenous bases.
Part 2: DNA Replication
a. Now, using scissors, cut the toothpicks in your DNA down the space between the two marshmallows on each "rung" of the DNA.
b. Now, using the Twizzlers, marshmallows, and toothpicks, build a complementary strand for each half of your section of DNA
Data
Make a color drawing of the two steps in this process in your notebook. You should have a color drawing of the "unzipped" section of DNA AND the original and duplicated strands of DNA in your notebooks.
Part 3: Mutations
Pick one of the two strands of DNA you now have. Now, you can create mutations by doing one of the following:
a. Trade one base pair for another (remember to follow the base pairing rules). This is called substitution.
b. Remove one of the base pairs. This is called deletion.
c. Add a base pair. This is called insertion
Data
Make a drawing of your mutated strand of DNA in your notebook. As with the other drawings, this one should be in color.
Part 4: Protein Synthesis
In this part, you will be acting out the process of protein synthesis for a section of DNA. Please do the following:
a. Create a section of DNA with 6 base pairs (be sure to follow the base pairing rules). Make a color drawing of your section of DNA in your notebook.
b. Unzip your section of DNA using scissors. Make a color drawing of the two halves.
c. Make a complementary strand of mRMA using the black Twizzlers as the sugar-phosphate back bone of the mRNA. Make a color drawing of your strand of mRNA.
d. Make two pieces of tRNA that complement your strand of RNA. Make color drawing of your pieces of tRNA.
e. Use the codon chart (see below) to determine the amino acids put together by your original strand of DNA. Write these (in order) in your notebooks.
Data
Make the drawings and collect other data specified in the instructions above.
Analysis and Conclusions
Please answer the questions below. Your answers should be in full sentences and you should incluced as much detail as possible.
1. What did you learn about the structure of DNA?
2. What did you learn about how DNA replicates itself?
3. What did you learn about mutations?
4. What did you learn about Protein Synthesis?
5. Given what you now know about DNA Replication, Mutations, and Protein Synthesis, what is the end result of a mutation? Is this harmful or beneficial?