(N/A) According to Francis Crick,there is a mechanism to read the genetic code and link it to amino acids.
Amino acids do not have any structural features that allow them to recognize the genetic code directly.
Crick postulated the presence of an adapter molecule that could read the genetic code on one side and bind to specific amino acids on the other.
$t-RNA$ (formerly known as $s-RNA$) acts as this adapter molecule.
$t-RNA$ has an anticodon loop that contains bases complementary to the code on $m-RNA$,and it has an amino acid acceptor end to which the specific amino acid binds.
For each amino acid,there is a specific $t-RNA$. There is another specific $t-RNA$ for initiation,called initiator $t-RNA$. There are no $t-RNA$ molecules for stop codons.
The secondary structure of $t-RNA$ is clover-leaf shaped,but in its actual three-dimensional structure,$t-RNA$ is an inverted $L$-shaped molecule.