Question

The most important function of mRNA is to

• A. Provide specific binding sites for a series of specific tRNA molecules
• B. Hold a group of ribosomes together
• C. Transfer the genetic code to ribosomal RNA
• D. Transfer the genetic code to DNA

Answer 1

The correct option is A Provide specific binding sites for a series of specific tRNA molecules

Each tRNA contains a template-recognition site called as an anticodon which contains a sequence of three bases that are complementary to the codon on the mRNA. The anticodon loop recognizes the mRNA template and binds to the appropriate codon by complementary base pairing. This base pairing of tRNA anticodon and mRNA codon is key to protein synthesis as tRNA serves to bind its specific amino acid and carry it to the growing end of a polypeptide chain if the next codon in the mRNA required it. Multiple ribosomes attached to the mRNA bearing nascent growing polypeptide chains are known as polysomes which serve to synthesize the multiple copies of a protein simultaneously. Protein synthesis can be carried out with the single copy of ribosome attached to mRNA. Statement C is incorrect because mRNA carries the genetic code transcribed from DNA in the form of a series of three nucleotide sequences, called codons. This genetic code is transferred to a polypeptide in the form of sequence and types of amino acids. Statement D is incorrect because the rRNA and associated proteins forms ribosomes which physically move along an mRNA molecule and catalyze the formation of polypeptide chains. The correct answer is A.