Question

The following sequence represents triplets on DNA: TAC CAG ATA CAC TCC CCT GCG ACT a. Give the mRNA codons and tRNA anticodons th b. c. Induce an insertion of one nucleotide in the original sequence? Do the same for 2 nucleotides then 3 d. Substitute one nucleotide in the original sequence. How does each insertion affect the amino acid at correspond with this sequence, and then give the sequence of amino acids in the polypeptide. induce a deletion in one of the nucleotide codons. How does the deletion affect the amino acid sequence? nucleotides. How does each insertion affect the amino acid sequence? sequence? i. Which of your induced mutations are frameshift mutations? ii. Which of your mutations are nonsense? ii. Are any of your induced mutations missense? iv. Which of the types of mutations are most likely to cause damage or problems for the cell?

Answer 1

a.                                  TAC CAG ATA CAC TCC CCT GCG ACT

mRNA                       AUG GUC UAU GUG AGG GGA CGC UGA

tRNA anticodon         CUAC CAG AUA CAC UCC CCU GCG ACU

protein                       MET VAL TYR VAL ARG GLY ARG STOP

b. deletion

DNA sequence      TAC CAG ATA CAC TC CCT GCG ACT

mRNA                    AUG GUC UAU GUG AGG GAC GCU GA

protein                   MET VAL TYR VAL ARG ASP ALA GA

c. insertion 1 nucleotide

      TAC CAG AAT ACA CTC CCC TGC GAC T

mRNA      AUG GUC UUA UGU GAG GGG ACG CUG A

protein    MET VAL LEU CYS GLU GLY THR LEU A

insertion at 2 nucleotide

           TAC CAG ATA CAC TCC GGC CTG CGA CT

mRNA       AUG GUC UAU GUG AGG CCG GAC GCU GA

protein        MET VAL TYR VAL ARG PRO ASP ALA GA

d.    TAC CAG ATA CAC TCC CCT GCG ACT

substitute sequence           TAC GAG ATA CAC TCC CCT GCG ACT

mRNA                  AUG CUC UAU GUG AGG GGA CGC UGA ´

protein    MET LEU TYR VAL ARG GLY ARG STOP              

original protein                MET VAL TYR VAL ARG GLY ARG STOP