Question

3'- CCA TGT CCG GAA GTG AAT- 5' Using the same template DNA strand provided in question #1, transcribe and translate the DNA strand after the following mutations have occurred. You only need to provide the new amino acid sequence of the protein encoded after these mutations have occurred: a. A "C" to "T" base substitution at nucleotide position #8. b. A "T" to "C" base substitution at nucleotide position #6. c. Which one of these is more likely to have a negative impact on the cell? Explain your answer.

Answer 1

3'- CCA TGT CCG GAA GTG AAT- 5' ( original template DNA strand )

5'- CCA UGU CCG GAA GUG AAU- 3' ( original template DNA strand )

Pro Cys Pro Glu Val Asn ( original peptide)

a) "C" to "T"

3'- CCA TGT CTG GAA GTG AAT- 5' ( mutated template DNA strand )

5'- CCA UGU CUG GAA GUG AAU- 3' ( mutated template mRNA strand )

  Pro Cys Leu Glu Val Asn ( Mutated peptide)

b) "T" to "C"

3'- CCA TGC CCG GAA GTG AAT- 5' ( mutated template DNA strand )

5'- CCA UGC CCG GAA GUG AAU- 3' ( mutated template mRNA strand )

  Pro Cys Pro Glu Val Asn ( Mutated peptide)

"C" to "T" base substitution at nucleotide position #8 is more likely to have a negative impact on the cell, because it will change the amino acid from proline to leucine while "T" to "C" base substitution at nucleotide position #6 has no effect on , the amino acid will remain same ( UGC & UGU both codes for cysteine).