What is the primary purpose of anti-codons in nucleic acids?

• A. To initiate $\mathrm{DNA}$ replication
• B. To pair with codons on $\mathrm{mRNA}$ during protein synthesis
• C. To carry amino acids to the ribosome
• D. To stabilize the $\mathrm{DNA}$ double helix

Answer: (B)

Verified step by step guidance

1. Understand the role of anti-codons: Anti-codons are sequences of three nucleotides found on tRNA molecules. Their primary purpose is to pair with complementary codons on mRNA during protein synthesis.
2. Recognize the process of translation: During translation, mRNA is decoded to build a protein. tRNA molecules, each with a specific anti-codon, bring the appropriate amino acids to the ribosome.
3. Identify the pairing mechanism: The anti-codon on tRNA pairs with the codon on mRNA through complementary base pairing, ensuring that the correct amino acid is added to the growing polypeptide chain.
4. Clarify the role of tRNA: tRNA acts as an adaptor molecule, translating the genetic code from mRNA into a sequence of amino acids, which are the building blocks of proteins.
5. Distinguish from other functions: Anti-codons do not initiate DNA replication or stabilize the DNA double helix; their function is specific to protein synthesis during translation.