"Experiment 1: Coding Procedure
A) Using 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
B) 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
1. 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.
2. What does the sentence say now? (re-read the entire sentence)
Mutations are simply changes in the sequence of nucleotides. There are three ways this occurs
Change one, remove one, or add one
Using the sentence from exercise 1B
B) Change the 24th bead to a different color.
3. What does the sentence say now? (re-read the entire sentence)
4. Does it make sense?
D) Replace the 24th bead and remove the 20th bead (remember what was there).
5. What does the sentence say (re-read the entire sentence)?
6. Does it make sense?
7. Where does it make sense?
E. Replace the 20th bead and add one between bead numbers 50 and 51.
8. What does the sentence say?
9. Does it make sense?
10. In “C” we mutated one letter. What role do you think the redundancy of the genetic code plays, in light of this change?
11. Based on your observations, why do you suppose the mutations we made in “D” and “E” are called frame shift mutations.
12. Which mutations do you suspect have the greatest consequence? Why?
DNA codes for all of the proteins manufactured by any organism (including you!). It is valuable, highly informative and securely protected in the nucleus of every cell.
You don’t have to do the transcription/translation bead assignment continue to Experiment 3, DNA extraction.
Complete the DNA extraction as instructed in the lab and answer the following questions.
1. Which DNA bases pair with each other?
2. How is information to make proteins passed on through generations?
3. Why did we use a salt in the extraction solution?
4. What else might be in the ethanol/aqueous interface? How could you eliminate this?
5. What is the texture and consistency o DNA?
6. Is the DNA soluble in the aqueous solution or alcohol?
7. What surprised you about DNA replication and protein synthesis?"