Which of the following is a primary role of mRNA?

The primary role of mRNA, or messenger RNA, is to bear the message for protein synthesis. mRNA is synthesized during transcription, where a specific segment of DNA is copied into RNA. This RNA then serves as a template that carries genetic information from the DNA in the nucleus to the ribosomes, the cellular machinery responsible for translating that information into proteins.

During the translation process, mRNA provides the necessary code that dictates the sequence of amino acids in a protein, ultimately determining the structure and function of the protein being synthesized. This role is crucial because proteins perform a vast array of functions within living organisms, including enzymes, structural components, signaling molecules, and more.

The other options do not accurately describe the function of mRNA. While cellular metabolism involves various biomolecules, mRNA itself does not carry out these processes directly. The structural framework of ribosomes is primarily formed by ribosomal RNA (rRNA), not mRNA. Finally, while DNA stores genetic information, mRNA functions more as a messenger that conveys that information necessary for creating proteins rather than storing it.