Difference Between Genetic Code and Codon

Key Difference – Genetic Code vs Codon
 

DNA, the genetic material of all organisms, carries genetic information in the form of genes. They are encoded with all the instructions which are necessary to make proteins. The genes are transcribed into mRNA sequences and then translated into amino acid sequences which make proteins. There is a precise nucleotide sequence in a gene. It is responsible for the correct order of the amino acids of the protein to be synthesized. Genetic code and codon are important words used in gene expression. There are four types of bases in DNA. The genetic code is the precise nucleotide or the base sequence of the DNA of a gene which is responsible for making the mRNA which results in the protein. When the genetic code is divided into groups of three bases (triplets), one base group can be referred as a codon which is responsible for a specific amino acid. This is the key difference between genetic code and codon.

CONTENTS
1. Overview and Key Difference
2. What is a Genetic Code
3. What is a Codon
4. Side by Side Comparison – Genetic Code vs Codon
5. Summary

What is Genetic Code?

The genetic code of a gene is responsible for the synthesis of the correct amino acid sequence of a protein. Therefore, the genetic code can be defined as the precise base sequence of a gene which results in the correct codon sequence, deciding the correct amino acid sequence of a protein. The genetic code of the sense strand of the gene is delivered into the mRNA strand by a process known as transcription. Then, the mRNA strand composes the correct base sequence to make the codon sequence which is responsible for the production of the amino acid sequence of the protein. The difference of one base in the genetic code is enough to result in an incorrect amino acid sequence leading to a wrong protein production.

The genetic code of a gene determines the amino acid sequence of the protein to be synthesized. The genetic code is actually hidden in the DNA in the form of three base groups called codons. Changes in the nucleotides in the genetic code determine the changes in the amino acid sequence.

Characteristics of the Genetic code

• It is made up of triplets known as codons.
• It is degenerative.
• The code is nonoverlapping.
• The code is commaless.
• The code is nonambiguous.
• The code is universal.
• There are initiation and termination codons.

What is Codon?

A codon is a three base group which specifies an amino acid of a polypeptide. Hence, every three bases of sense DNA strand or mRNA strand can be considered as codons. There are four bases in nucleic acids. Thus, these four bases can produce a total of 64 different triplets resulting in a total of 64 codons. Three codons are not coded for amino acids; they are known as stop codons. Other 61 codons make different amino acids. There are 20 different amino acids in proteins. Hence, each amino acid can be coded by more than one codon. As an example, amino acid serine coded by six codons namely UCU, UCC, UCA, UCG, AGU, and AGC.

A codon contains a unique order of three bases. Therefore, codons can be easily identified and the amino acids they result in can be determined. By analyzing the codon sequence, it is easy to construct the amino acid sequence of the protein. Codons are read into amino acids by the ribosomes of the cells.

What is the difference between Genetic Code and Codon?

Summary – Genetic Code vs Codon

The genetic code is the correct order of bases in a particular DNA sequence which is responsible for the production of the amino acid sequence of a protein. A codon is a base triplet which specifies a particular amino acid of a protein. There are 64 possible codons by the four bases in the nucleic acids. Codon sequence gives the correct amino acid sequence. Therefore the genetic code is also can be known as a collection of codons. This is the difference between genetic code and codon.

References:
1. Koonin, Eugene V., and Artem S. Novozhilov. “Origin and evolution of the genetic code: the universal enigma.” Iubmb Life. U.S. National Library of Medicine, Feb. 2009. Web. 22 Mar. 2017
2. Lobanov, Alexey V., Anton A. Turanov, Dolph L. Hatfield, and Vadim N. Gladyshev. “Dual functions of codons in the genetic code.” Critical Reviews in Biochemistry and Molecular Biology. U.S. National Library of Medicine, Aug. 2010. Web. 22 Mar. 2017

Image Courtesy:
1. “Genetic code” By Madprime – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “RNA-codons-aminoacids” By Thomas Splettstoesser (www.scistyle.com) – Own work (CC BY-SA 4.0) via Commons Wikimedia