What is the role of messenger RNA (mRNA) in protein synthesis?

Messenger RNA (mRNA) plays a crucial role in protein synthesis by carrying genetic information from DNA to the ribosome, where proteins are synthesized. During transcription, a specific segment of DNA is copied into mRNA. This mRNA strand then exits the nucleus and enters the cytoplasm, where it serves as a template for the assembly of amino acids into proteins. The sequence of nucleotides in the mRNA is translated into a specific sequence of amino acids, ultimately leading to the formation of a functional protein.

Understanding the function of mRNA is essential in the broader context of molecular biology, as it connects the DNA, which contains the genetic blueprint, to the ribosomes—the sites of protein synthesis. This process highlights the central dogma of molecular biology: DNA -> mRNA -> Protein, illustrating how genetic information is expressed.

In contrast, the roles of the other options do not align with the primary function of mRNA in protein synthesis. Transporting amino acids to the ribosome is primarily the role of transfer RNA (tRNA). DNA replication involves other enzymes and mechanisms unrelated to the function of mRNA. Structural support in cells is typically provided by proteins, cytoskeleton components, and other structures rather than mRNA.