The Central Dogma

CENTRAL DOGMA

The Central Dogma of genetics is: DNA is transcribed to RNA which is translated to protein. Protein is never back-translated to RNA or DNA; and except... click here to read more

The Central Dogma of genetics is: DNA is transcribed to RNA which is translated to protein. Protein is never back-translated to RNA or DNA; and except for retroviruses, DNA is never created from RNA. Furthermore, DNA is never directly translated to protein. DNA – RNA – protein.

Transcription of DNA to RNA and translate to protein. This dogma forms the backbone of molecular biology and is represented by four major stages.

The DNA replicates its information in a process that involves many enzymes – replication.

The DNA codes for the production of messenger RNA (mRNA) during transcription.

In eukaryotic cells, the mRNA is processed (essentially by splicing) and migrates from the nucleus to the cytoplasm.

Messenger RNA carries coded information to ribosomes. The ribosomes "read" this information and use it for protein synthesis. This process is called translation.

Proteins do not code for the production of protein, RNA or DNA. They are involved in almost all biological activities, structural or enzymatic.

DNA is the long term hard-copy of the genetic material; by way of analogy it is similar to information stored on a computer's hard-disk drive. DNA is very stable and inert (that's kinda the point of DNA).

RNA is a temporary intermediary between DNA and the protein making factories, the ribosomes. RNA could be compared to information stored in a cache in that the lifetime of RNA is much shorter than that of either DNA or the average protein, and also RNA serves to carry information from the genome, located in the nucleus of the cell, to the ribosomes, which are located outside of the nucleus either in the cytosol or on the endoplasmic reticulum.

Proteins could be viewed as the programs of the cell (to complete our analogy). They are the physical representation of the abstract information contained within the genome. Proteins vary greatly in their activity and halflife. Example of protein such as collagen, it makes up the bulk of you hair, tendons, skin, and ligaments. In contrast to collagen, take lactase, the enzyme that allows you to digest lactose (enzyme is also an exampe of protien). Lactose is the sugar found in milk and dairy products. Lactose intolerant people have a faulty lactase gene and cannot digest lactose. Hormones are proteins as well. Insulin, for example, is a protein that your body uses to signal various organs to take up sugar from the blood stream.

DNA REPLICATION

Prior to cell division, the DNA material in the original cell must be duplicated so that after cell division, each new cell contains the full amount of DNA material. The process of DNA duplication is... click here to read more

TRANSCRIPTION

Transcription is the process through which a DNA sequence is enzymatically copied by an RNA polymerase to produce a... click here to read more

TRANSLATION

Eventually the mature mRNA finds its way to a ribosome, where it is translated into a protein, another biological polymer. In prokaryotic cells, which have no nuclear compartment, the process... click here to read more

Last updated on 23 March 2008