HOME>> TRANSLATION>> ADVANCED LOOK>> 1.) MRNA>> 2.) INITIATION>> 3.) ELONGATION>> 4.) TERMINATION

Translation: Advanced Look --> 4.) Termination

Termination occurs 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.

To see the Quicktime movie for the following sequence of images, click here.

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 the ribosome.
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, polypeptide proteins.

HOME>> TRANSLATION>> ADVANCED LOOK>> 1.) MRNA>> 2.) INITIATION>> 3.) ELONGATION>> 4.) TERMINATION