Question

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”.

                E:            H:            I:            K:            L:

_ _ __ _ __ _ __ _ __ _ __ _ _

               O:           S:            T:            U:

_ _ __ _ __ _ __ _ __ _ _

Create codons for:    Start:            Stop:            Space:

                 _ _ _            _ _ _              _ _ _

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

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.

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)

Using the sentence from exercise 2B:

Change the 24^th bead to a different color. What does the sentence say now (re-read the entire sentence)? Does the sentence still make sense?

Replace the 24^th bead and remove the 20^th 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?

Replace the 20^th bead and add one between bead numbers 50 and 51. What does the sentence say now? Does the sentence still make sense?

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?

Based on your observations, why do you suppose the mutations we made in 3.b and 3.c are called frame shift mutations?

Which mutations do you suspect have the greatest consequence? Why?

Answer 1

YRG BRY YYY BBB RGR GYB YBR GBR RBG BBB RGR BYG GGG RBY BBB RBG RGR RRR YYY BBB BBB RBG BBB BGY

c.

The mouse likes cheese

3.

Using the sentence from exercise 2B:

Change the 24th bead to a different colour. What does the sentence say now (re-read the entire sentence)? Does the sentence still make sense?

yellow:blue:red (Start) blue:yellow:green (T) red:blue:red ( H )red:green:red (E) red:green:yellow (Space) yellow:green:yellow (M)green:yellow:green (O) yellow:green:Yellow (M)red:blue:yellow (S)red:green:red (E) red:green:yellow (Space) Yellow:blue:yellow (L)Blue:red:blue (l) Blue:yellow:blue (K) red:green:red (E) red:blue:yellow (S)red:green:yellow (Space) yellow:green:yellow (M) green:yellow:green (O)red:blue:yellow (S) blue:yellow:green (T) red:green:yellow (Space)green:red:green (C) red:blue:red (H) red:green:red (E) red:green:red (E)red:blue:yellow (S) red:green:red (E) green:yellow:blue ( STOP)

The momse likes most cheese. The Sentence does not make any sense.

Replace the 24th bead and remove the 20th bead (remember what was there).

yellow:blue:red (Start) blue:yellow:green (T) red:blue:red ( H ) red:green:red (E) red:green:yellow (Space) yellow:green:yellow (M) blue:yellow:green (T) yellow:green:red (U) red:blue:yellow (S) red:green:red (E) red:green:yellow (Space) Yellow:blue:yellow (L) Blue:red:blue (l) Blue:yellow:blue (K) red:green:red (E) red:blue:yellow (S) red:green:yellow (Space) green:red:green (C) red:blue:red (H) red:green:red (E)

red:green:red (E) red:blue:yellow (S) red:green:red (E) green:yellow:blue ( STOP)

The mtuse likes cheese.

Does it make sense?

NO

Where does it make sense?

No where

Replace the 20th bead and add one between 50 & 51.

yellow:blue:red (Start) blue:yellow:green (T) red:blue:red ( H ) red:green:red (E) red:green:yellow (Space) yellow:green:yellow (M) green:yellow:green (O) yellow:green:red (U) red:blue:yellow (S) red:green:red (E) red:green:yellow (Space) Yellow:blue:yellow (L) Blue:red:blue (l) Blue:yellow:blue (K) red:green:red (E) red:blue:yellow (S) red:green:blue:yellow (Space) green:red:green (C) red:blue:red (H) red:green:red (E) red:green:red (E) red:blue:yellow(S) red:green:red (E) green:yellow:blue ( STOP)

The mouse likescheese

Does it make sense?

No.

The genetic code has 64 codons which code for 20 amino acids. The ability of the redundancies allows for different variation of codons to code for the same amino acids. The benefit of this is that even if there is a mistake in the base pairing, the amino acid might be unaffected. Basically, this allows amino acids to be represented in more than on combination.

Based on your observations, why do you suppose the mutations we made in “D” and “E”

are called frameshift mutations?

Frameshift mutations are the type of mutation caused by the addition or deletion of a base pair in the DNA resulting in the translation of the genetic code in an unnatural reading frame from the position of the mutation to the end of the gene. In the Mutations, we made in “D” and “E”, we added and deleted beads resulting in an incorrect sentence which does not make sense.

Which mutations do you suspect have the greatest consequence? Why?

I would say Frameshift mutations are the worst. DNA is read in triplets so everything would get moved forward or backwards.