During translation, the ribosome reads the code in which molecule?

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

Answer: (C)

During translation the ribosome uses the message carried by messenger RNA to determine the order of amino acids in a protein. mRNA contains codons, each three-nucleotide unit that specifies a particular amino acid through the genetic code. The ribosome reads these codons and, with the help of tRNA delivering the matching amino acids, links them together to form a polypeptide. The molecule that actually brings the amino acids, tRNA, acts as an adaptor and is not the code being read. rRNA is part of the ribosome’s structure and helps catalyze the reaction, but it does not carry the coding sequence. DNA provides the original template for transcription but is not read directly during translation. So the code read by the ribosome during translation is carried by messenger RNA.