Which statement about glycine codons is accurate according to the material?

Which statement about glycine codons is accurate according to the material?

• A. Glycine is coded by a single codon only.
• B. Glycine is not coded by any codon.
• C. Glycine is coded by different amino acids.
• D. CCC and CCT code for glycine.

Answer: (D)

Codons are sets of three nucleotides that specify which amino acid gets added during protein synthesis. Glycine is encoded by four codons in RNA: GGU, GGC, GGA, and GGG. When you look at the DNA language (the coding strand), these map to GGT, GGC, GGA, and GGG, respectively. The idea that CCC and CCT code for glycine would mix up the actual codon table, because those triplets correspond to proline in the mRNA (CCU, CCC, CCA, CCG). So glycine is not coded by CCC and CCT; that statement isn’t accurate.

Codons are sets of three nucleotides that specify which amino acid gets added during protein synthesis. Glycine is encoded by four codons in RNA: GGU, GGC, GGA, and GGG. When you look at the DNA language (the coding strand), these map to GGT, GGC, GGA, and GGG, respectively. The idea that CCC and CCT code for glycine would mix up the actual codon table, because those triplets correspond to proline in the mRNA (CCU, CCC, CCA, CCG). So glycine is not coded by CCC and CCT; that statement isn’t accurate.