Central Dogma
‘The Central Dogma’ of molecular biology is the term used to describe how the genetic information stored within DNA is first encoded into RNA and then used to produce functional proteins within the cell.[1] Although DNA contains all the genetic information needed to produce proteins, it uses RNA as an intermediary molecule to transfer the information, thus RNA molecules are often referred to as the ‘messenger’ molecules (mRNA), transferring the genetic information from DNA in order to produce proteins.[2]
DNA contains very specific sequences of nucleotides which can act as a template for a strand of RNA to be produced through the process of transcription. The resulting strand of RNA then codes for a very specific sequence of amino acids. These can be joined together in the ribosome of the cell to produce a polypeptide chain in a process known as translation. Hence, all the information that is needed to make proteins initially comes from DNA molecules.[3]
Thus, the Central Dogma explains the flow of genetic information and can be expressed as: DNA - RNA - Proteins, where the genetic information that is stored in DNA, is passed to RNA and then used to make a useful protein within the cell.[4]
However, whilst this concept is true for the majority of our genes, recent studies have shown that not every gene found in DNA codes for a protein. In fact some sequences of DNA can code for various types of RNA.[5]
The Central Dogma is also essential to the RNA World Hypothesis.
References
- ↑ Becker, W., Hardin, J., Bertoni, G. and Kleinsmith, L.J. (2012) Becker’s World of the Cell. 8th Edition. San Francisco: Pearson Benjamin Cummins. (p. 645)
- ↑ Hartl, D.L. and Ruvolo, M. (2012) Genetics. 8th Edition. Burlington, MA: Jones & Bartlett Learning. (pp. 22-23).
- ↑ Hartl, D.L. and Ruvolo, M. (2012) Genetics. 8th Edition. Burlington, MA: Jones & Bartlett Learning. (pp. 22-23).
- ↑ Becker, W., Hardin, J., Bertoni, G. and Kleinsmith, L.J. (2012) Becker’s World of the Cell. 8th Edition. San Francisco: Pearson Benjamin Cummins. (p. 645)
- ↑ National Centre for Biotechnology Information (2007) Central Dogma of Biology: Classic View. Available at: http://www.ncbi.nlm.nih.gov/Class/MLACourse/Modules/MolBioReview/central_dogma.html (Accessed: 28/11/14)