How many stop codons exist in the genetic code?

There are three stop codons in the genetic code, which play a crucial role in the process of protein synthesis. These stop codons are essential signals that indicate the termination of translation during protein synthesis. When a ribosome encounters a stop codon on an mRNA strand, it stops adding amino acids to the growing polypeptide chain, leading to the release of the completed protein.

The specific stop codons are UAA, UAG, and UGA, and they do not code for any amino acids. Instead, their presence signifies to the ribosome that the translation process should cease, thus ensuring that proteins are synthesized to the correct length and structure. This precise function is vital for maintaining proper cellular function and preventing the formation of dysfunctional proteins that could arise from translational errors. Understanding the role of stop codons is fundamental when studying the genetic code and the mechanisms underlying gene expression.