How would the following insertion mutation of an adenine in the 3rd codon affect the amino acid chain produced in the following sequence…
Original mRNA strand- AUG GCU UGG CCC UAA
Mutated mRNA strand- AUG GCU UAG GCC CUA A
a) The ribosome would not be able to translate the mRNA with this mutation
b) The ribosome would make proline instead of alanine
c) The ribosome would receive a stop codon at an earlier spot, so the correct protein would not be made

Question

How would the following insertion mutation of an adenine in the 3rd codon affect the amino acid chain produced in the following sequence… 
Original mRNA strand- AUG  GCU  UGG  CCC  UAA
Mutated mRNA strand- AUG  GCU  UAG  GCC  CUA  A
a)	The ribosome would not be able to translate the mRNA with this mutation 
b)	The ribosome would make proline instead of alanine
c)	The ribosome would receive a stop codon at an earlier spot, so the correct protein would not be made

anonymous · Answer

c) since UAG is a stop codon, see the RNA codon table in the wikipedia article for codons