'Second Genetic Code' and 'Second Half of the Genetic Code'
In the next main topic we will discuss about the 'Second Genetic Code' and 'Second Half of the Genetic Code'. A distinction, therefore, needs to be made of these two expressions from 'The Genetic Code' described in this section. As already mentioned earlier in this section, the genetic code is meant for translation of the language of nucleic acid into that of protein, using triplet codons. However, the 'Second Genetic Code' refers to the mechanism involved in the interaction of specific tRNAs with corresponding amino acyl synthetase enzymes (how does an enzyme recognize its tRNA or vice versa ?) and the 'Second Half of the Genetic Code' refers to the protein folding problem or to the rules, which govern the formation of a three dimensional structure from the primary structure (amino acid sequence) of a protein. Both these problems remain only partly resolved and continue to receive attention of molecular biologists.