Final answer:
Suppressor tRNAs compete with release factors for binding to the ribosomes when a stop codon is reached during translation, potentially extending the polypeptide chain beyond its normal end.
Step-by-step explanation:
Suppressor tRNAs compete with release factors. During the process of translation, the ribosome accepts charged tRNAs. These tRNAs interact with three main components: they must be recognized by aminoacyl synthetase, recognized by ribosomes, and bind to the correct sequence in mRNA. However, when a stop codon is reached, there is normally no tRNA that has an anticodon matching these codons. Instead, the translation halts briefly, allowing release factors to bind and signal the termination of protein synthesis. This involves the hydrolysis of the terminal peptidyl tRNA, release of the completed polypeptide, and dissociation of the ribosomal subunits. Suppressor tRNAs are specialized tRNAs that can recognize stop codons and insert an amino acid at this site, which competes with the binding of release factors, potentially allowing translation to continue and the polypeptide to extend past the normal termination point.