Question

Which one of the following statements is true for protein synthesis (translation)?

• A. Amino acids are directly recognized by mRNA
• B. The third base of the codon is less specific
• C. Only one codon codes for an amino acid
• D. Every tRNA molecule has more than one amino acid attachment site

Answer 1

The correct option is B The third base of the codon is less specific

For protein synthesis, mRNA carries information and tRNA brings amino acids to the ribosomes. Each tRNA is specific for a particular amino acid and has only one amino acid attachment site.

Certain amino acids can be coded by more than one codon, hence codons show degeneracy. To explain degeneracy, wobble hypothesis was proposed. According to this hypothesis, the first two bases of the codon have precise pairing with the anti codon on tRNA, while the pairing of 3rd base of codon and anticodon may wobble (less specific).