Central dogma of molecular biology

The central dogma of molecular biology is an explanation of the flow of genetic information within a biological system. It refers to the flow of information from deoxyribonucleic acid (DNA) to ribonucleic acid (RNA) and finally into proteins. The DNA to RNA conversion is carried out in a process called transcription. Then, the subsequent RNA sequence will be translated into protein in a process called translation. The process is summarized in figure 1.

A circular arrow at the top of a DNA strand labeled DNA replication, DNA to DNA. The circle indicates DNA polymerase. A black arrow points down from the DNA strand to a single-stranded RNA strand. This arrow is labeled DNA to RNA transcription and represents RNA polymerase. Another arrow points down from the single-stranded RNA molecule to an amino acid chain. This arrow is labeled RNA to protein and represents the ribosome.

Figure 1: Central Dogma of molecular biology. DNA to RNA transcription is mediated by the RNA polymerase and then, RNA to protein translation is mediated by the ribosome.

There are some exceptions to this dogma which resulted from recent years genomic studies. For example, much of the DNA that does not encode proteins is now known to encode various types of functional RNAs.