Genetic Mutations and Proteins
Objective: The student will evaluate how gene mutations affect the production of proteins.
Procedure:
1. Use the template strand of a DNA molecule and write the base sequence for an mRNA that
would be transcribed. Place your results in the table below.
2. Use the table on page 2 to determine the sequence of amino acids in the resulting protein
fragment. Place your results in the table below.
3. If the fourth base in the original DNA strand were changed from G to C, how would this
affect the resulting protein created? Write the new mRNA strand and protein fragments in the
table below.
4. If a G were added to the original DNA strand after the third base, what would the resulting
mRNA look like? How would this addition affect the protein? Show your results in the table
below.
Data:
Template DNA strand
AAT GTG AAC ACA TGC GCC ATC
Transcribe mRNA sequence
Protein Sequence from Step 2
New template DNA strand from
Step 3
AAT CTG AAC ACA TGC GCC ATC
New mRNA from Step 3
New Protein Sequence from
Step 3
New template DNA strand from
Step 4
New mRNA from Step 4
New Protein Sequence from
Step 4
AAT GGT GAA CAC ATG CGC CAT C
Analysis Questions:
1. Is it more damaging to the final protein to change one base or insert a base? Why?
2. Is it possible to have a base change in a DNA sequence that does not affect the protein
produced? If so, how?
3. Using the original DNA sequence provided above, delete one of the bases from the sequence.
Write your new DNA sequence below. Then, transcribe the new mRNA that would be created
from your new DNA sequence. Finally, write the amino acid sequence that would be translated
from your mRNA.
4. Which step in the procedures does Analysis question 3 relate to most? Why?