Transfer RNA ( tRNA) are species of RNA responsible for the transfer of specific amino acids to the growing end of a polypeptide chain during translation. R.Holly in 1965 gave clover leaf model of tRNA for yeast alanyl tRNA. It has four major sites - AAbinding site, anticodon site, TUC loop and DHU loop. The chain is having unpaired base sequence CCA at 3'-end and G at 5'-end.