What is the primary function of transfer RNA (tRNA)?

The primary function of transfer RNA (tRNA) is to direct polypeptide synthesis. tRNA serves as the adapter molecule that translates the genetic code carried by messenger RNA (mRNA) into a specific sequence of amino acids to form proteins. Each tRNA molecule is responsible for bringing a particular amino acid to the ribosome, the site of protein synthesis. During translation, the anticodon region of tRNA pairs with the corresponding codon on the mRNA strand, ensuring that the correct amino acid is incorporated into the growing peptide chain based on the sequence of the mRNA. This process is crucial for building proteins that perform various functions within the cell and organism.

Other functions mentioned, such as binding DNA during replication, synthesizing mRNA, or facilitating the entrance of amino acids into ribosomes, do not accurately describe the role of tRNA. These processes involve other molecules and mechanisms, specifically DNA polymerases for replication and ribosomal RNA (rRNA) in the ribosome for translation, but tRNA's main role remains the direct involvement in translating genetic information into functional proteins.