Experiment 1: Coding:
1. Using the red, blue, yellow and green beads, devise and lay out a three color code for each of the following letters (codon).
For example Z = green : red : green.
In the spaces below the letter, record your "code".
C: E: H: I: K: L:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
M: O: S: T: U:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Create codons for: Start: Stop: Space:
_ _ _ _ _ _ _ _ _
2. Using this code, align the beads corresponding to the appropriate letter to write the following sentence (don't forget start, space and stop): The mouse likes most cheese
a. How many beads did you use?
There are multiple ways your cells can read a sequence of DNA and build slightly different proteins from the same strand. We will not go through the process here, but as an illustration of this "alternate splicing", remove codons (beads) 52 - 66 from your sentence above.
b. What does the sentence say now? (re-write the entire sentence)
Mutations are simply changes in the sequence of nucleotides. There are three ways this occurs:
1. Change a nucleotide(s)
2. Remove a nucleotide(s)
3. Add a nucleotide(s)
3. Using the sentence from exercise 1B:
a. Change the 24th bead to a different color. What does the sentence say now (re-read the entire sentence)? Does the sentence still make sense?
b. Replace the 24th bead and remove the 20th bead (remember what was there). What does the sentence say (re-read the entire sentence)? Does the sentence still make sense? If it doesn't make sense as a sentence, are there any words that do? If so, what words still make sense?
c. Replace the 20th bead and add one between bead numbers 50 and 51. What does the sentence say now? Does the sentence still make sense?
d. In 3.a (above) you mutated one letter. What role do you think the redundancy of the genetic code plays in this type of change?
e. Based on your observations, why do you suppose the mutations we made in 3.b and 3.c are called frame shift mutations?
f. Which mutations do you suspect have the greatest consequence? Why?
Experiment 2: Transcription and Translation:
1. Use a pen or pencil to write a five word sentence using no more than eight different letters in the space below.
2. Now, use the red, blue, green, and yellow beads to form "codons" (three beads) for each letter in your sentence. Then, create codons to represent the "start, "space" and stop" regions within your sentence. Write the sentence using the beads in the space below:
3. How many beads did you use?
4. Assign one Pop-It® bead to represent each codon. You do not need to assign a Pop-It® bead for the start, stop and space regions. These will be your amino acids.
5. Connect the Pop-It® beads to build the chain of amino acids that code for your sentence (leave out the start, stop, and space regions).
6. How many different amino acids did you use?
7. How many total amino acids did you use?
Experiment 3: DNA Extraction:
1. Describe the procedure that you used to extract DNA.
2. What is the texture and consistency of DNA?
3. Is the DNA soluble in the aqueous solution or alcohol?
4. Which DNA bases pair with each other? How many hydrogen pairs are shared by each pair?
5. How is information to make proteins passed on through generations?