Question

Which of the following DNA sequences might code for the polypeptide sequence Gly-Leu-Asp ?

5' GGG CUA GAU 3'

3' GAC TTA GGA 5

' 3' GGC TTG GAT 5'

3' CCA AAC CTG 5''

5' GGC CTT GAA 3'

Answer 1

First of all, transcription occurs in the DNA sequence that has a direction from 3’ to 5’. So, option a and e are incorrect.

The correct answer is:

3' CCA AAC CTG 5’’

mRNA: GGU UUG GAC

Amino acid sequence: GGU (Gly), UUG (Leu), GAC (Asp)

To known the amino acid sequence that codes the mRNA you need the genetic code in your textbook or internet.