How does DNA specifically code for proteins?

The correct answer highlights the crucial role of RNA in the process of protein synthesis, which is often described as the central dogma of molecular biology. In this process, DNA serves as the template for creating messenger RNA (mRNA) through transcription. During transcription, the DNA double helix unwinds, and RNA polymerase synthesizes a strand of mRNA complementary to the DNA strand. Once the mRNA is formed, it then undergoes processing and is transported out of the nucleus into the cytoplasm.

During translation, the mRNA is read by ribosomes, which facilitate the assembly of amino acids into polypeptide chains based on the sequence of codons in the mRNA. Each codon corresponds to a specific amino acid or a stop signal during protein synthesis. Therefore, DNA does not directly code for proteins; instead, it first codes for RNA, which then carries the information required to build proteins by linking together the appropriate amino acids in the correct sequence. This understanding emphasizes the intermediary role of RNA in the flow of genetic information from DNA to the final protein product.