What is the primary function of tRNA in protein synthesis?

The primary function of tRNA in protein synthesis is to join amino acids into a chain. Transfer RNA (tRNA) plays a crucial role during the translation phase of protein synthesis. Each tRNA molecule carries a specific amino acid and has an anticodon that is complementary to the codon on the mRNA. This ensures that the correct amino acid is added to the growing polypeptide chain according to the sequence specified by the mRNA.

When the ribosome assembles an amino acid chain, tRNA molecules transport the appropriate amino acids to the ribosome, where they are linked together in the sequence determined by the mRNA. This process is essential for translating genetic information into functional proteins, highlighting the importance of tRNA in connecting the genetic code to protein structure.

The other choices address different processes that do not accurately reflect the role of tRNA. For example, coding for DNA pertains to the action of DNA itself, while transcribing mRNA is a function of RNA polymerase during transcription rather than tRNA. Additionally, replicating DNA involves enzymes and processes related to DNA itself, separate from the roles played by tRNA in protein synthesis.