Codons are typically presented in the language of messenger RNA (mRNA) because messenger RNA is the intermediary molecule that carries genetic information from the DNA to the cellular machinery involved in protein synthesis.
The genetic information in DNA is stored in the form of a sequence of nucleotide bases, which are represented by the letters A, T, G, and C. However, DNA cannot directly participate in protein synthesis. Instead, it is transcribed into mRNA through a process called transcription.
During transcription, the DNA sequence is copied into mRNA, which is a single-stranded molecule. The mRNA is complementary to DNA, so it uses the bases A, U, G, and C (replacing thymine with uracil) to complement the DNA bases. This means that the mRNA sequence will have a complementary base pair for every DNA base pair.
Once the mRNA sequence is formed, it can leave the nucleus and move to the ribosomes in the cytoplasm, where it interacts with transfer RNA (tRNA) molecules and the amino acids they carry.
Codons are three-nucleotide sequences on the mRNA molecule that code for specific amino acids. Each codon corresponds to one of the 20 common amino acids found in proteins. The language of mRNA is used because it is the direct template for the synthesis of proteins. The ribosomes "read" the mRNA codons and match them with the corresponding tRNA molecules, which bring in the appropriate amino acids. This allows for the correct sequence of amino acids to be assembled during protein synthesis, based on the mRNA instructions.
In summary, codons are presented in the language of mRNA because mRNA acts as the messenger between the DNA code and the protein synthesis machinery in the cell. By using the mRNA language, the codons can be correctly translated into the sequence of amino acids that will make up a protein.
why codons usually presented in the language of messenger RNA
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