Study Guide 4 Question 8

Question 1

What substitution mutation would produce the following amino acid chain?

Met, Val, Iso, Glu, Thr, Trp, Gln, Arg, Arg, Arg, Tyr, Asn, (stop)

Answer 1

Only the sixth amino acid differs. Trp is coded by UGG, indicating a substitution of G for U in the second position of the sixth codon.

Question 2

What substitution mutation would produce the following amino acid chain?
What frameshift mutation would have the same effect?

Met, Val, Iso, (stop)

Answer 2

substitution mutation: the correct codon is GAG, a substitution of U for G in the first position would create this amino acid chain

frameshift mutation: Since UGA is also a stop codon, an insertion of a U between the third and fourth
codons would also produce this effect