Codon | Anticodon Introduction, Chart & Examples

By | July 24, 2019


A codon is a triple sequence of DNA and RNA that corresponds to a specific Amino acid. It describes the relationship between DNAís sequence bases (A, C, G, and T) in a gene and the corresponding protein sequence that it encodes. The triplet of bases in DNA encoded amino acid.

How Many Codons Are There?

Generally, there are 64 sixty-four diverse Codons (4 ◊ 4 ◊ 4 = 64). It is one of 64 possible triplets of the four nucleic acid bases. After synchronization of the gene in RNA, the triplets are represented by the four bases of RNA, (thymine being replaced by uracil). DNA and RNA molecules are written in the language of nucleotides. Temporarily, the philological of proteins comprises 20 amino acids. Codons provide a way in which these two languages can be translated into each other. Codons have a close similarity to a single amino acid and a full group of codons called genetic code.

Codon Chart††††††


Where is a Codon Found?

Anticodons are found on molecules of transfer RNA. They operate nucleotide with the sequence on a strand of mRNA throughout the translation. This action ensures that the proper amino alkanoic acid is value-added to the growing peptide chain. A transfer RNA molecule can enter the ribosome guaranteed to an organic compound.

Anticodon Definition

Anticodons are basically the section of a transfer RNA (t RNA) is a categorization of three bases which are corresponding to codons in the mRNA. During the translation process, the Anticodon bases form corresponding base sets among the bases of the codon by establishing the suitable hydrogen bonds.


Anticodon Definition Biology

Sequences of nucleotides that are complementary to codons are called anticodon. They are found in tRNAs and allow the tRNAs to take correct amino acid in a way with mRNA during protein production. During protein production, amino acid bounded together into a string, such as beads on the bracelet. The correct amino acid must be used in incorrect places because amino acids have different properties. If a wrong amino acid put in a spot can render a protein useless, or even dangerous for the cell.

The function of Anticodons:

The function of anticodons is to take correct amino acid together to create a protein, based on the instructions carried in mRNA. Every tRNA carries one anticodon and has one amino acid. When the anticodon successfully pairs up with mRNA codons, the correct amino acid is in place to be added to the growing protein.

Anticodons are compulsory to complete the process of turning the information stored in DNA into a functional protein. Thatís a cell can use to carry out its life functions.

Codon and Anticodon


Codon vs Anticodon†

Reading Frame of Codon:

Open Reading Frame Finder

Codons have three letters the genetic code can be interpreted in three ways. These three ways are called Reading Frames. For an instant, the gene CGAGCCTCC, if we read from the first position (or frame), it contains the codons CGA, GCC, TCC. If we read from the second position (or frame), it contains the codons GAG and CCT. If read by third position (or frame), it contains AGC and CTC codons. Because the code is read as triplets codons each the second and third reading frames just contain two complete codons.

6 Reading Frames are described below:

As a result, in the genetic code, by reading frames every DNA sequence or gene can be read in three different forms. Each different frame will generate a different amino acid sequence when it transmitted because amino acid has different properties. Only one frame is actually a correct frame and generates a viable protein. The other two frames will wrong. In our cells, the actual frame in which a protein sequence is translated is defined by a Start codons and terminated with Stop codons.

Codon Example


How Many Codons Equal One Amino Acid:

Individually codon codes only single amino acid, numerous amino acids are roundabout multiple of codons because there are 64 thinkable groupings of bases of DNA.


Genetic Code Diagram


Genetic Code Chart

Properties of Genetic Code

Characteristics of the Codon are described below:

  1. Triplet nature
  2. Degeneracy
  3. No overlapping
  4. Non-ambiguity
  5. Polarity
  6. Comma less
  7. Universality
  8. Chain initiation codons
  9. Chain termination codons
  • Triplet Nature:

A triplet code can be grouped for 64 different combinations (4*4*4) genetic codes and gives the information in DNA molecule to specify the placement of all 20 amino acids. When experiments were done on the genetic code, a triplet code was found. These three-letter codes (AUG, AAA, etc.) are called codons.

  • Degeneracy:

The same amino acid is coded by more than one base triplet, which is code generated. For instance, three amino acids arginine, alanine, and leucine have six similar codons.

  • No overlapping:

The genetic code never does overlapping, thatís mean the adjacent codon never overlap each other. A no overlapping code means that two different codons did not use the same letter.

  • Non-Ambiguity:

The same amino acid always coded by a particular codon. In fact, one codon (the codon is generated) can be a code the same amino acid, but the same codon shall not code for two or more different amino acids (non-ambiguity).

  • Polarity:

The genetic code is polar means that the code always read in a fixed direction.

  • Comma less:

The genetic code is comma free. The genetic code has no signal to indicate the one end of codon and the beginning of other.

  • Universality:†

Universality, the most important characteristic of the genetic code, means that the three base sequences encoded the same amino acid in all life from simple organism to complex one, for instance, human being.

  • Chain Initiation Codons:

In the genetic code, the AUG & GUG play a double role in E. coli. When both codons occur in between the two ends of cistron, amino acid coded by methionine and valine, in an intermediate position in the protein molecule.

  • Chain Termination Codons:

The three triplets UAA, UAG, UGA never coded for any amino acid. These codons describe as non-sense codons, against the remaining 61 codons out of 64 codons, which are described as sense codons.

DNA Codon Table


RNA Codon Table


Start & Stop Codon:

In the genetic code, there are two punctuation marks in the genetic code which start and end the protein synthesis in all organisms. These are called Start & Stop codons.

Start Codon:

The start codon is the codon that gives initial signal translation is a process that leads to the string formation of amino acids when anticodons present on the transfer of RNA molecule attached on mRNA. Our bodies create protein by this for various functions perform in bodies. After transcription of RNA, translation follows when a ribosome latches itself to an mRNA strand. The ribosome moves to mRNA until it recognizes a start codon, and their translation starts.

The start codons always work for methionine in eukaryotes and modified Met (fMet) in prokaryotes. AUG is the most common start codon. The start codon is often coded by 5íuntranslated regions (5í UTR).


Stop Codon:

stop codon definition: The stop codon is the codon that gives end signals to terminate protein synthesis. In 64 combinations of three bases, 61 specify an amino acid, while remaining three combinations are stop codons. These three codons are UUA, UAG, and UGA. These codons also called termination codons or nonsense codons.


Amino Acid Codon Table