Why are stop and start codons necessary for the proper functioning of protein synthesis?

Stop and start codons are necessary for the proper functioning of protein synthesis because they signal the beginning and end of protein translation. The start codon initiates the process of protein synthesis, while stop codons signal the termination of translation, ensuring that the protein is made correctly and in the right sequence. Without these codons, the protein synthesis process would not be able to start or stop at the correct points, leading to errors in protein production.