Six letters takes you up to 256 Codons;
MRNA is read in three-letter sections called Codons.
A four-letter alphabet gives you 64 possible Codons, which yield 20 amino acids,
the building blocks of proteins.
Later, we proved the exact number of three nucleotides(this is a unit of the genetic code),
which was called a triplet or codon.
For example, if the mRNA has triplet Codons like Uracil- Uracil-
Uracil( in short written as UUU) then it codes for the amino acid phehylalanine.
Instead, they are recognized by proteins called release factors, namely RF1(recognizing the UAA and UAG stop Codons)
or RF2 recognizing the UAA and UGA stop Codons.
The codon restriction theory is based on the assumption
that the accuracy with which the triplet Codons in mRNAs are translated into amino acids is lost with age.
Codon Restriction Theory:
The theory proposed by American scientist, B. L. Strehler states that aging occurs due to a malfunction in the most essential act of the cell? that of protein synthesis.