When using a codon chart to determine which amino acid will be incorporated during translation, which type of RNA codon should you look up on the chart?

• A. The tRNA anticodon (read 3′→5′)
• B. The amino acid sequence of the growing polypeptide
• C. The DNA template strand triplet (read 3′→5′)
• D. The mRNA codon (read 5′→3′)

Answer: (D)

Verified step by step guidance

1. Understand that the codon chart is designed to translate RNA codons into amino acids during the process of translation.
2. Recall that mRNA codons are read in the 5′→3′ direction, and each codon consists of three nucleotides that specify a particular amino acid.
3. Recognize that tRNA anticodons are complementary and antiparallel to mRNA codons, so they are read 3′→5′, but the codon chart does not use anticodons directly.
4. Note that the DNA template strand is read 3′→5′ to synthesize the mRNA strand, but the codon chart does not use DNA sequences; it uses mRNA codons.
5. Therefore, when using a codon chart, you should look up the mRNA codon sequence in the 5′→3′ direction to determine which amino acid will be incorporated.