Why are there only 45 different tRNA anticodons rather than 64 to match each of the mRNA codons?

There are only 45 different tRNA anticodons because of what is known as wobble. While you would expect each tRNA anticodon to pair with its codon and an amino acid so that there could be 64 tRNA anticodons, there are actually 45 tRNA anticodons. The reason is that the third nucleotide or base of a tRNA anticodon can recognize more than two codons on a messenger RNA.

For instance, a nucleoside known as inosine can bond with uracil, adenine, or cytosine. The phenomenon that explains this is known as wobble base pairing. This type of base pairing does not follow Watson-Crick base pair rules. It does not follow Watson-Crick base pair rules because wobble base pairing allows flexibility, and that is why inosine can bond with more than one codon of a messenger RNA.

It is important to note that there are about four major wobble base pairs. They are hypoxanthine-cytosine, hypoxanthine-adenine, hypoxanthine-uracil, and guanine-uracil.

The third nucleotide of the tRNA anticodon will make sure that some flexibility will be allowed. For those who are not familiar with what an anticodon is, this is a type of trinucleotide sequence that is complementary to the mRNA sequence.

You can expect that an anticodon can be found at one of the ends of the tRNA molecule. The main function of this is to base pair with the codon on the strand of the mRNA. This usually happens during translation. By this process, it can be ensured that amino acid will be added to the polypeptide chain.

There are 64 codons in a genetic code. Of the 64 codons, 61 code for amino acids, which are the building blocks of proteins. Although 61 different codons code for 20 amino acid, there are only 45 different tRNAs for the reason that the third base in the tRNA anticodon can recognize two or more codons on mRNA.

The capacity to acknowledge codons is called wobble. Wobble is the reason why there are only 45 different tRNA anticodons rather than 64. Wobble can be described as a relaxation of base-pairing rules in the first position of an anticodon of a tRNA molecule.

The third base of a codon is termed the wobble position. It plays a smaller role in determining which amino acid is coded for the first and second bases.