1. Got materials?
Pencil
Mutation Lab Handout
Brains

2. An introduction to Point Mutation
Mutations by An logy
An introduction to
Point Mutation
After this lesson students will be able to
identify three types of point mutation:
substitution, insertion, and deletion;
and predict & explain the effect of these
genetic mutations coding for
mRNA on protein synthesis.

3. Language Arts question:
What is an ANALOGY?

4. INSTRUCTIONS
Every three bases on the mRNA codes for an amino acid. Every three bases of our “Secret Pseudo-Protein Code” codes for a letter or punctuation mark. Since our “Secret Pseudo-Protein Code” is more familiar, we will use it to examine mutations. Remember the same rules hold for both codes:
All messages must begin with START.
There are no spaces between three letter words; one simply counts every three letters.

5. H a l l o ! H e l l o ! One letter was changed.
Original message:
A U G G U G U U C A C U A C U G C A U A A
Point substitution mutation:
A U G G U G A U C A C U A C U G C A U A A
What was the effect of this mutation?
If this had been an mRNA coding for a protein, what would have been changed? H a l l o !
| | | | | | | | H e
l l o !
| | | | | | | |
One letter was changed.
One amino acid was changed.

6. Message stopped prematurely.
2. Original message:
A U G A C A U C A U G G A G A G A U C A A A U C
Point deletion mutation:
A U G A C A U C A U G A G A G A U C A A A U C
What was the effect of this mutation?
If this had been an mRNA coding for a protein, what would have been changed? m i x t u r e
| | | | | | | |
m i .
| | | | | | | |
Message stopped prematurely.
Only part of protein synthesized.

7. Did the size of this mutation’s EFFECT surprise you?
Answer this:
Did the size of this mutation’s EFFECT surprise you?

8. Wrong letters & no STOP code
3. Original message:
A U G G A G U C U U U C A A A U A G U A G A G G
Point insertion mutation:
A U G G A G U C U U U C A A U A U A G U A G A G G
What was the effect of this mutation?
If this had been an mRNA coding for a protein, what would have been changed? W h a t ?
| | | | | | | | | g W
W h a s F
| | | | | | | | |
Wrong letters & no STOP code
Longer, but nonfunctioning, protein

9. NO message because no start
Original message:
A U G U A U C A A G C A A A A A U C U C A G C U
Point substitution mutation:
G U G U A U C A A G C A A A A A U C U C A G C U
What was the effect of this mutation?
If this had been an mRNA coding for a protein, what would have been changed? P r o t e i n
| | | | | | | | |
| | | | | | | | |
NO message because no start
NO protein because no start (met)

10. L a t e r . L a t e r . NO change in message NO change in protein
5. Original message:
A U G C C G U U C A A A A U C C A A U G A G C U
Point substitution mutation:
A U G C C G U U C A G A A U C C A A U G A G C U
What was the effect of this mutation?
If this had been an mRNA coding for a protein, what would have been changed? L a t e r .
| | | | | | | | |
L a t
e r
| | | | | | | | |
NO change in message
NO change in protein

11. Redundant:
Definition: excess, wordy
The code is redundant; there is more than one way to code for the same amino acid.

12. The mutation was actually in the DNA base-pair order.
During this activity you modeled protein synthesis using mRNA. But where did the mutation originally occur?
The mutation was actually
in the DNA base-pair order.

13. change in base order of DNA in a cell’s chromosome.
7. What is a mutation?
A mutation is a
change in base order of DNA
in a cell’s chromosome.

14. changes in order, &/or number, of amino acids in the protein.
8. How can a change in the DNA cause a change in an organism’s protein?
Change in DNA causes
change in mRNA causes
changes in order, &/or number, of amino acids in the protein.

15. Most amino acids (& STOP) have more than one code.
9. Do all mutations in the DNA coding for mRNA cause a change in an organism? Why or why not?
NO!
Code is redundant:
Most amino acids (& STOP) have more than one code.
Some changes in base order do NOT cause changes in amino acids .

16. 10. Are mutations helpful or harmful?
Some mutations can be helpful .
Disease resistance Hallo!  Hello!
Some mutations can be harmful .
Cancer What?  WhaSFgW
Many mutations are often neutral .
Little/no change Later.  Later.

17. 10. Are mutations helpful or harmful?
Can be helpful , harmful, neutral.
Whether a mutation is good or bad is often a function of the environment .
Sickle cell anemia
Stress  blood cells change shape
 pain, strokes, etc.
 Can’t catch malaria!

18. Got name?