How many codons are required to encode a protein consisting of 10 amino acids?

How many codons are required to encode a protein consisting of 10 amino acids?

• A. 10
• B. 30
• C. 20
• D. 40

Answer: (A)

Each codon is a triplet that specifies one amino acid during translation. To build a protein with 10 amino acids, the ribosome needs 10 codons—one for each amino acid in the sequence. The stop codon that ends translation is not an amino acid, so it isn’t counted among the 10 that encode the protein. If you were counting nucleotides instead of codons, that coding region would be 30 nucleotides long (10 codons × 3 nucleotides), but the number of codons is what matters here. Therefore, ten codons are required.

Each codon is a triplet that specifies one amino acid during translation. To build a protein with 10 amino acids, the ribosome needs 10 codons—one for each amino acid in the sequence. The stop codon that ends translation is not an amino acid, so it isn’t counted among the 10 that encode the protein. If you were counting nucleotides instead of codons, that coding region would be 30 nucleotides long (10 codons × 3 nucleotides), but the number of codons is what matters here. Therefore, ten codons are required.