Download Lab—Gene Mutations A gene mutation is a change in the

Lab—Gene Mutations
A gene mutation is a change in the sequences of bases within a gene. There are three type of mutations: 1.) Substitution; 2.)
Deletion; 3.) Insertion. In this lab, we will investigate these mutations and determine what effect they have on the polypeptide
chain they produce.
From Normal Gene to Normal Polypeptide Chain:
DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC
mRNA Sequence:_______________________________________________________________
Amino acid Sequence:___________________________________________________________
Simulating Mutations:
Substitution:
Normal DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC (same as above)
Simulate substitution by replacing the 5th base (bolded) in the normal gene with a G:
Mutated DNA Sequence:_____________________________________________________________
New mRNA Sequence: ______________________________________________________________
New amino acid Sequence: __________________________________________________________
-How many amino acids are different from the original? _______________________
-What are the new amino acids that were not present in original? _________________________
Deletion:
Normal DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC (same as above)
Simulate Deletion by removing the 5th base (bolded) in the normal gene. All bases should shift over 1 position to the left.
Mutated DNA Sequence: ________________________________________________________________
New mRNA Sequence: __________________________________________________________________
New amino acid Sequence: ______________________________________________________________
-How many amino acids are different? _______________________________
-What are the new amino acids that were not present in the original? _______________________________________________
Insertion:
Normal DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC (same as above)
Simulate Insertion by inserting an extra base in the 5th base position (bolded)—do not remove any original bases this time) All
other bases should shift over one position to the right.
Mutated DNA Sequence: __________________________________________________________________
New mRNA Sequence: ____________________________________________________________________
New Amino Acid Sequence: ________________________________________________________________
-How many amino acids were different? ______________________________
-What are the new amino acids that were not present in the original? ______________________________________________
Lab—Gene Mutations
A gene mutation is a change in the sequences of bases within a gene. There are three type of mutations: 1.) Substitution; 2.)
Deletion; 3.) Addition. In this lab, we will investigate these mutations and determine what effect they have on the polypeptide
chain they produce.
From Normal Gene to Normal Polypeptide Chain:
DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC
mRNA Sequence:_______________________________________________________________
Amino acid Sequence:___________________________________________________________
Simulating Mutations:
Substitution:
Normal DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC (same as above)
Simulate substitution by replacing the 5th base (bolded) in the normal gene with a G:
Mutated DNA Sequence:_____________________________________________________________
New mRNA Sequence: ______________________________________________________________
New amino acid Sequence: __________________________________________________________
-How many amino acids are different from the original? _______________________
-What are the new amino acids that were not present in original? _________________________
Deletion:
Normal DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC (same as above)
Simulate Deletion by removing the 5th base (bolded) in the normal gene. All bases should shift over 1 position to the left.
Mutated DNA Sequence: ________________________________________________________________
New mRNA Sequence: __________________________________________________________________
New amino acid Sequence: ______________________________________________________________
-How many amino acids are different? _______________________________
-What are the new amino acids that were not present in the original? _______________________________________________
Addition:
Normal DNA Sequence: TAC ATA GAT CTG CTT CCG AGA AGC ATC (same as above)
Simulate Addition by inserting an extra base in the 5th base position (bolded)—do not remove any original bases this time) All
other bases should shift over one position to the right.
Mutated DNA Sequence: __________________________________________________________________
New mRNA Sequence: ____________________________________________________________________
New Amino Acid Sequence: ________________________________________________________________
-How many amino acids were different? ______________________________
-What are the new amino acids that were not present in the original? ______________________________________________
Questions:
1. What are the 3 types of mutations?
2. Which mutation caused the most drastic change
in the amino acid sequence (polypeptide chain)?
3. What would happen to the polypeptide chain if a
mutation :
a. Produced a STOP codon at beginning of gene?
b. Omitted a START codon at the beginning of a gene?
4. When would substitution mutation cause no change
in the resulting polypeptide chain?
5. Why do you think addition and deletion mutations are
called frameshift mutations?
Questions:
1. What are the 3 types of mutations?
2. Which mutation caused the most drastic change
in the amino acid sequence (polypeptide chain)?
3. What would happen to the polypeptide chain if a
mutation :
a. Produced a STOP codon at beginning of gene?
b. Omitted a START codon at the beginning of a gene?
4. When would substitution mutation cause no change
in the resulting polypeptide chain?
5. Why do you think addition and deletion mutations are
called frameshift mutations?