Here's a breakdown:
* Stop Codons: These are specific three-nucleotide sequences within the mRNA that signal the end of a protein-coding region. There are three stop codons: UAA, UAG, and UGA.
* Release Factors: When a ribosome encounters a stop codon, it attracts proteins called release factors.
* Termination: Release factors bind to the stop codon and trigger the following events:
* The polypeptide chain is released from the ribosome.
* The tRNA in the A site is ejected.
* The ribosome subunits (small and large) dissociate from the mRNA.
Key Points:
* Translation doesn't necessarily end at the very end of the mRNA molecule. There might be untranslated regions (UTRs) after the stop codon.
* The process of translation termination is highly regulated and involves several proteins and factors.
Let me know if you have any other questions!