What molecule carries amino acids to the ribosome during protein synthesis?

• A. tRNA
• B. mRNA
• C. rRNA
• D. DNA

Answer: (A)

The molecule that carries amino acids to the ribosome during protein synthesis is tRNA (transfer RNA). Each tRNA molecule is specific to one amino acid and has an anticodon region that pairs with a corresponding codon on the mRNA strand being translated at the ribosome. This pairing ensures that the correct amino acid is added to the growing polypeptide chain in accordance with the sequence encoded by the mRNA.

During the process of translation, the ribosome facilitates the binding of tRNA to the mRNA template. As each tRNA brings its specific amino acid, the ribosome catalyzes the formation of peptide bonds between these amino acids, elongating the polypeptide chain until a stop codon is reached on the mRNA.

In contrast, mRNA (messenger RNA) serves as the template that carries the genetic information from DNA to the ribosome, rRNA (ribosomal RNA) is a structural component of the ribosome, and DNA holds the genetic code but does not participate directly in the transport of amino acids. Thus, tRNA's role in delivering amino acids is crucial for the synthesis of proteins according to the genetic instructions provided by mRNA.