Question

A segment of DNA, GCCAGGGGATG, was translated into the oligopeptide arginine-serine- praline-tyrosine.

1. What was the base sequence in the mRNA transcribed from the DNA segment?
2. What are the codons for the 4 amino acids?
3. If the first adenine in the DNA segment gets substituted by guanine, what will be the:
   1. mRNA transcript?
   2. sequence of amino acids in the new oligopeptide?
   3. anticodons on tRNA for the amino acids?

Answer 1

1. The base sequence in the mRNA transcribed from the DNA segment is CGG UCC CCC UAC.
2. The codons for the four amino acids are CGG for Arginine, UCC for Serine, CCC for Proline, and UAC for Tyrosine.
3. 1. The new mRNA transcript will be CGG CCC CCC UAC.
   2. The new sequence of amino acids will be Arginine – Proline – Proline – Tyrosine.
   3. The anticodons on the tRNA for these amino acids will be GCC, GGG, GGG, and AUG.