Identify the amino acid carried by tRNAs with the following anticodon sequences.

5′-UAG-3′

Key Concepts

tRNA and Anticodons

Transfer RNA (tRNA) is a type of RNA molecule that helps decode a messenger RNA (mRNA) sequence into a protein. Each tRNA molecule has an anticodon, a sequence of three nucleotides that is complementary to a corresponding codon on the mRNA. The anticodon ensures that the correct amino acid is added during protein synthesis.

Codon-Amino Acid Relationship

In the genetic code, a codon is a sequence of three nucleotides on mRNA that specifies a particular amino acid. The relationship between codons and amino acids is defined by the genetic code, which is nearly universal among organisms. For example, the codon UAG is a stop codon, which signals the termination of protein synthesis rather than coding for an amino acid.

Stop Codons

Stop codons are specific sequences in mRNA that signal the end of translation, the process of synthesizing proteins. The three stop codons—UAA, UAG, and UGA—do not correspond to any amino acids and instead instruct the ribosome to release the newly formed polypeptide chain. In this case, the anticodon 5′-UAG-3′ indicates that the tRNA does not carry an amino acid but rather signals the termination of protein synthesis.