Q. 17.46 - An Introduction to General, Organic, and Biological Chemistry

Question

The codons$\mathrm{UGA}, \mathrm{UAA}$, and $\mathrm{UAG}$ do not code for amino acids. What is their role as codons in $\mathrm{mRNA}$?

Step-by-Step Solution

Answer

          During translation, codons in an $\mathrm{mRNA}$ are read, starting with a start codon and continuing until a stop codon is reached. The order of amino acids in a protein from the $\mathrm{N}$-terminus (methionine) to the $\mathrm{C}$-terminus is specified by $\mathrm{mRNA}$ codons, which are read from $5\text{'}$ to $3\text{'}$.

Step 1: Introduction

        There are three codons in the human genome that do not code for any amino acids. The stop codons, also known as terminator codons, are $\mathrm{UAA}, \mathrm{UAG}$, and $\mathrm{UGA}$. They are situated near the end of the mRNA and signal the translation to stop and the protein to be released.

Step 2: Explanation

          During translation, codons in an $\mathrm{mRNA}$ are read, starting with a start codon and continuing until a stop codon is reached. The order of amino acids in a protein from the $\mathrm{N}$-terminus (methionine) to the $\mathrm{C}$-terminus is specified by $\mathrm{mRNA}$ codons, which are read from $5\text{'}$ to $3\text{'}$.

Step 3: Conclusion