Talk:Central Dogma

The central dogma of molecular biology was a theory first postulated by Francis Crick in 1970 and to this day, is still widely accepted. The basic idea for the hypothesis is as follows: Polynucleotides and polypeptides use RNA as an intermediate in their two-component system, or more simply: DNA ---> RNA ---> Protein.   The idea relies on the ability of the polynucleotides to encode proteins using their genetic information and the polypeptides' catalytic activity which includes enzymes able to synthesise DNA. Thus, the central dogma can be said to be based on the two processes: Transcription and Translation. 

In transcription, a section of DNA is copied into RNA using RNA polymerase. In translation, mRNA with a specific codon bind to specific ribosomes in the cell. tRNA with the specific anti-codon, as well as a specific amino acid sequence, then bind to the mRNA and the existing amino acid sequence binds to the newly introduced sequence forming a peptide bond and hence a protein. 

The two processes go hand in hand and furthermore, the whole central dogma theory is founded upon the irreversibility of the translation process. Crick hypothesized the theory after the discovery of reverse transcriptase as the discovery of such an enzyme made it clear that, without very complicated molecular machinery, it is impossible to go from a protein to nucleic acids.