Tuesday, 18 December 2007

An introduction to molecular biology (part I)


My wife has been pestering me to contribute something for our blog. So I though I'll give you an overview of my PhD topic. Enjoy.....

The so called 'central dogma of molecular biology' states that information in a living cell flows from DNA to RNA to protein. DNA can be thought of as the information store in the cell. This information is encoded in the arrangement of 4 chemical letters that form the DNA. The information stored in the DNA is what is referred as the genetic make up of an organism.

On the other end of the spectrum, proteins are really the work horses or the machineries that run the cell. Most of the interesting stuff like immune response, metabolism, and even motility (cell movement) are at a large extend due to the working of many proteins.

Bridging between DNA and protein is RNA. Traditionally RNA has been viewed as merely an messenger between the two big guys. However recent discovery of the role of RNA interference (which by the way won the Nobel prize in biology) opens up a whole new world in our understanding of RNA.

To go back to our original discussion, the three players in cell are DNA, RNA, and protein. The process of creating RNA from DNA is called transcription, while the process of producing protein from RNA is called translation. These two processes are highly regulated (controlled). To illustrate this point, virtually all cells in your body contain exactly the same DNA (the same information), nonetheless some grew into brain cells, some into skin cells, others into muscle cells, etc, which meant that they have different composition of proteins. How is that possible? I'll tell you in the next post... :)

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