What is the structure of messenger RNA?

Messenger RNA (mRNA) is primarily characterized as being single-stranded. This structure allows it to serve as a template for protein synthesis. The single-stranded nature of mRNA facilitates its ability to be transcribed from a DNA template in the nucleus and then translated by ribosomes in the cytoplasm.

The linear characteristics of mRNA support its role in carrying genetic information from the DNA to the ribosome, where this information is used to synthesize proteins according to the code contained within the mRNA sequence. Each mRNA strand consists of ribonucleotides that correspond to the coding information of a gene, following the principle of complementary base pairing during transcription.

The double-stranded structure is typical of DNA rather than mRNA, as DNA's double helix is essential for its stability and replication. The concept of tripled-stranded or alternative forms is not applicable to the conventional understanding of mRNA structure in cellular biology. Thus, the identification of mRNA as single-stranded is a fundamental aspect of its function in transcription and translation processes.