The primary role of transfer RNA (tRNA) in protein synthesis is to serve as an adapter molecule that translates the genetic code from messenger RNA (mRNA) into a specific sequence of amino acids, thereby constructing proteins. Each tRNA molecule has a specific amino acid attached to one end and an anticodon on the other end that is complementary to a corresponding codon on the mRNA.
During translation, the ribosome facilitates the binding of the appropriate tRNA to the mRNA strand, allowing the tRNA to deliver its associated amino acid to the growing polypeptide chain. This process continues until a stop codon is reached, ultimately resulting in the formation of a complete protein. Thus, tRNA plays a crucial role in ensuring the correct sequence of amino acids is assembled according to the genetic information encoded in the mRNA.