Question

Help with Bio!

Answer 1

Benzene, a known carcinogen, mutates a sequence of DNA in a gene. The previous sequence contained TAC GGC ACG TTT ATT, and the mutation caused the seventh nucleotide (with an adenine base) to be replaced by a nucleotide with cytosine base. How will the final mutated polypeptide be different from the original polypeptide?

Answer 2

A cysteine (cys) amino acid will be changed to a glycine (gly).

A cysteine (cys) amino acid will be changed to Leucine (leu).

A threonine (thr) amino acid will be changed to a glycine (gly).

A theorine (thr) amino acid will be changed to a leucine (leu).

Answer 3

@matt101 Please help!

Answer 4

@electrokid @ganeshie8 @SolomonZelman @tena32

Answer 5

@matt101

Answer 6

The mutated peptide changes the codon from ACG to CCG. However, keep in mind that this is DNA, and that proteins are produced from RNA. Therefore the sequence we're looking at is going to be complementary to this sequence: a UGC codon is changing to a GGC codon. According to your chart, this represents a mutation from a cysteine residue to a glycine residue (answer A).