Which human molecule carries genetic instructions from DNA to ribosomes?

Messenger RNA, or mRNA, carries genetic instructions from DNA to ribosomes.

During transcription, an RNA polymerase uses a DNA gene as a template to make a complementary RNA transcript. In eukaryotic human cells, the initial transcript is processed: introns are removed, exons are joined, and a cap and poly-A tail are added before mature mRNA leaves the nucleus.

At a ribosome, the mRNA sequence is read in three-letter units called codons. Transfer RNA molecules pair their anticodons with codons and deliver amino acids, allowing the ribosome to build a protein in the specified order.

Messenger RNA is not the same as DNA and does not normally serve as permanent genetic storage. It is also distinct from ribosomal RNA, which forms much of the ribosome’s structure, and transfer RNA, which brings amino acids. Human mRNA is temporary and is eventually broken down by cellular machinery.