What are the three stop codons?

What are the three stop codons?

• A. UGA, UAG, or UAA
• B. UAA, UGA, or UGG
• C. UGG, UAG, or UGA
• D. UAG, UAA, or UGA

Answer: (D)

Stop signals end translation. They are codons that do not code for amino acids but trigger termination of the polypeptide. The three stop codons in the standard genetic code are UAG (amber), UAA (ochre), and UGA (opal). When the ribosome encounters any of these, release factors promote cleavage of the finished polypeptide from the tRNA and dissociation of the ribosome. Other codons, like UGG, do encode amino acids (UGG codes for tryptophan), so any option that includes a non-stop codon cannot be the full set of stops. The correct trio is UAG, UAA, and UGA.

Stop signals end translation. They are codons that do not code for amino acids but trigger termination of the polypeptide. The three stop codons in the standard genetic code are UAG (amber), UAA (ochre), and UGA (opal). When the ribosome encounters any of these, release factors promote cleavage of the finished polypeptide from the tRNA and dissociation of the ribosome. Other codons, like UGG, do encode amino acids (UGG codes for tryptophan), so any option that includes a non-stop codon cannot be the full set of stops. The correct trio is UAG, UAA, and UGA.