Thread: Ribosome

In protein synthesis, how does the ribosome know when it has to stop adding amino acids to the growing polypeptide chain?

i know that it terminates when a release factor releases the chain, but how does it know when a functional polypeptide chain is complete?

Termination occurs when a stop codon on the RNA being translated (UAA, UAG and UGA) moves into the ribosome's aminoacyl site. The stop codon, which is not recognised by any aminoacyl-tRNAs is instead recognised by a release factor.