Small subunit attaches to mRNA. tRNA attaches to start codon mRNA. Large subunit attaches on top.
Parts of elongation:
new tRNA molecule attaches to mRNA at the A site of the ribosome. An enzyme forms a peptide bond between the amino acids. The initial tRNA molecule leaves the P site, and the ribosome shifts, restarting the process.
Parts of termination:
a stop codon reaches the A site, a releasing factor enters the A site, and a hydrolysis reaction breaks the bond. The polypeptide chain folds into a shape and becomes a protein.