Tuesday, August 28, 2007

Genetic material

•Ten things you didn't know about Wikipedia •
Genetic material
From Wikipedia, the free encyclopedia
Jump to: navigation, search

Genetic material is used to store the genetic information of an organic life form. For all currently known living organisms, the genetic material is almost exclusively Deoxyribonucleic Acid DNA. Some viruses use Ribonucleic Acid RNA as their genetic material.

The first genetic material is generally believed to have been RNA, initially manifested by self-replicating RNA molecules floating on bodies of water. This hypothetical period in the evolution of cellular life is known as the RNA world. This hypothesis is based on RNA's ability to act both as genetic material and as a catalyst, known as ribozyme or a ribosome. However, once proteins, which can form enzymes, came into existence, the more stable molecule DNA became the dominant genetic material, a situation continued today. Not only does DNA's double-stranded nature allow for correction of mutations but RNA is inherently unstable. Modern cells use RNA mainly for the building of proteins from DNA instructions, in the form of messenger RNA, ribosomal RNA, and transfer RNA.

Both RNA and DNA are macromolecules composed of nucleotides, of which there are four available in each molecule. Three nucleotides compose a codon, a sort of "genetic word", which is like an amino acid in a protein. The codon-amino acid translation is known as Translation (genetics).

A codon is composed of three base pairs, one base normally always being attached to one of the other bases. In other words, two normal combinations, which means that DNA was the first binary code. Forty-eight base pairs are in human Deoxyribonucleic Acid, which allows for about 2^48 (281 474 976 710 656) combinations. What's more is that, unlike many other organisms, the base pairs for humans are of nearly equal proportions, which probably reduces the number of viable combinations to more like 2^47.

Genetisists have also come up with rules that would make DNA repeat itself in palindromes, a characteristic that, if it were a strict rule, would cut the exponent (the number of bits in the above numbers) in half, to less than 2^24 (16.7 million) viable combinations.


This article does not cite any references or sources.
Please help improve this article by adding citations to reliable sources. (help, get involved!)
Unverifiable material may be challenged and removed.
This article has been tagged since August 2006.
Retrieved from "http://en.wikipedia.org/wiki/Genetic_material"

Categories: Articles lacking sources from August 2006 | All articles lacking sources | Genetics
Views

* Article
* Discussion
* Edit this page
* History

Personal tools

* Sign in / create account

Navigation

* Main page
* Contents
* Featured content
* Current events
* Random article

interaction

* About Wikipedia
* Community portal
* Recent changes
* Contact Wikipedia
* Donate to Wikipedia
* Help

Search

Toolbox

* What links here
* Related changes
* Upload file
* Special pages
* Printable version
* Permanent link
* Cite this article

In other languages

* עברית
* Bahasa Indonesia
* Íslenska
* Suomi
* ไทย
* Tiếng Việt
* Українська
* 中文

Powered by MediaWiki
Wikimedia Foundation

* This page was last modified 03:38, 16 July 2007.
* All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.)
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a US-registered 501(c)(3) tax-deductible nonprofit charity.
* Privacy policy
* About Wikipedia
* Disclaimers

Your continued donations keep Wikipedia running!