when a stop codon is encountered by the ribosome as it travels along the mRNA
strand. It signals the end of peptide chain growth, and the completion of a
protein. Clicking on each of the thumbnail images will bring up a larger,
labeled version of the described scene.
see the Flash movie for the following sequence of images,
No tRNA exists that recognizes the triplet
sequence in mRNA known as a stop codon. Instead, a release
factor enters the ribsome.
The release factor interferes with peptide elongation,
and the ribosome moves no further.
The peptide chain is released from the tRNA and leaves
With the peptide chain gone, the ribosome dissociates
into its individual large and small subunits.
Protein synthesis is now complete. The peptide chain
is ready to act as a protein or be combined with other chains to form larger,