Aminoacyl-tRNA is a molecule that plays a crucial role in protein synthesis. It consists of a specific amino acid attached to a transfer RNA (tRNA) molecule. Each tRNA is linked to a particular amino acid, which corresponds to a specific codon on the messenger RNA (mRNA) during translation. During the process of translation, aminoacyl-tRNA delivers the correct amino acid to the growing polypeptide chain at the ribosome. This ensures that proteins are assembled in the correct sequence, which is essential for their proper function in biological processes.