Q 34E - Organic Chemistry (Mcmurry)

Question

Question: What amino acid sequence is coded for by the following mRNA base sequence?
(5') CUA-GAC-CGU-UCC-AAG-UGA (3')

Step-by-Step Solution

Answer

The amino acid sequence for the given DNA, (5') CUA-GAC-CGU-UCC-AAG-UGA (3’) is: Leu-Asp-Arg-Ser-Lys-Stop

Step 1: Introduction to the Concept

Although DNA is double-stranded, only one strand is used as a transcription template at any given moment. The noncoding strand is the name given to this template strand. Because its sequence will be identical to that of the new RNA molecule, the nontemplate strand is referred to as the coding strand.

Step 2: Solution Explanation

From the question, mRNA sequence is

(5') CUA-GAC-CGU-UCC-AAG-UGA (3')

The message shows "Leu" from the code assignment table since the first base is C, the second base is U, and the third base is A. The first base in (GAC) is G, the second base is A, and the third base is C. As a result, the message reads "Asp".

The first base is C, the second base is G, and the third base is U in (CGU). As a result, the message reads "Arg". The first base is now U, the second base is C, and the third base is C. As a result, the message reads "Ser".

The first base in (AAG) is A, the second base is A, and the third base is G. As a result, the message reads "Lys". The last codon message is UGA, which stands for "Stop".

The fact that the last amino acid in the sequence is "Stop" indicates that the proper protein has been fully produced. The protein is released from the ribosome when a stop codon signal is received.