(N/A) Translation refers to the process of polymerization of amino acids to form a polypeptide chain.
The order and sequence of amino acids are defined by the sequence of bases in the $m-RNA$.
The amino acids are joined by a peptide bond. Formation of a peptide bond requires energy. Therefore,in the first phase,amino acids are activated in the presence of $ATP$.
This process is called charging of $t-RNA$ or aminoacylation of $t-RNA$. When two such charged $t-RNA$ molecules are brought close enough,the formation of a peptide bond between them is favored. The presence of a catalyst increases the rate of peptide bond formation.
The cellular factory responsible for protein synthesis is the ribosome. It consists of structural $RNAs$ and about $80$ different proteins. In its inactive state,it exists as two subunits: a large subunit and a small subunit.
When the small subunit encounters an $m-RNA$,the process of translation of the $m-RNA$ to protein begins. The large subunit has two sites for subsequent amino acids to bind to and thus be close enough to each other for the formation of a peptide bond.
The ribosome also acts as a catalyst ($23S$ $r-RNA$ in bacteria is the enzyme-ribozyme) for the formation of the peptide bond.
$A$ translational unit in $m-RNA$ is the sequence of $RNA$ that is flanked by the start codon $(AUG)$ and the stop codon and codes for a polypeptide. An $m-RNA$ also has some additional sequences that are not translated and are referred to as untranslated regions $(UTR)$.
The $UTR$s are present at both $5'$-end (before start codon) and $3'$-end (after stop codon). They are required for efficient translation process.