Let's briefly discuss what the structure of the tRNA molecule is. So the three dimensional structure of tRNA molecule is basically that of a cloverleaf. So basically, we have the following three dimensional regions. So we have the five end of our RNA molecule and we have the three end of that RNA molecule. And each one of these circles designates a single nucleotide. Now, these red regions are the regions where there is hydrogen bonding taking place between the tRNA nucleotides.