subject: Telomeres Definition And Information- Basics Of A Telomere [print this page] If you are like most people you have probably never heard of telomeres. However, it they are something that you should definitely know about. This article will provide you with telomeres definition and information, the basics of a telomere.
Telomeres
A telomere is the end of the chromosome that protects it from deterioration. It is a region of repetitive DNA that was first recognized by Alexei Olovnikov in 1971. What Olovnikov noticed was that chromosomes could replicate right up to the tip, so what he suggested was DNA sequences were lost at each phase of replication. However, when they reached a critical level cell division stopped. Enzymes that duplicate the chromosome and its DNA during cell division were not able to continue duplicating to the end of the chromosome. If a cell divided without telomeres, that cell would lose the end of its chromosomes, including the necessary information of how to replicate. This is a phenomenon called the end replication problem discovered in 1972 by James Watson. Essentially, a telomere is a disposable buffer that blocks the end of a chromosome. During cell division these telomeres are consumed and replenished by an enzyme known as telomerase reverse transcriptase. Between 1975 and 1977 Joseph Gall was working at Yale University and discovered the unusual nature of telomeres. What he found was that a telomere was simply a repeated DNA sequence that was composed at the end of a chromosome.
Telomeres and Cancer
He discovered that the shortening of telomeres limited cells to a fixed number of divisions. With further animal studies Gall discovered that telomeres were responsible for aging on the cellular level and that it sets a limit on lifespan. As soon as telomeres are consumed a cell is destroyed, except for when cancers are involved. Cancers create immortal cells that halt the normal phase of destruction. Telomeres and the nobel prize
The most recent news of telomeres came in 2009 when Elizabeth Blackburn, Carol Greider, and Jack Szostak won the Nobel Prize in Physiology or Medicine. They discovered how chromosomes are protected by telomeres and an enzyme called telomerase forms them. Telomeres have just recently been discovered and they are still being researched for us to further understand them. Research right now is going into finding how to lengthen telomeres because it is believed that can help extend life.
The basic information of telomeres has been talked about in this article. It can be difficult to understand what they are if you have trouble understanding science. Just remember that telomeres definition is a DNA sequence at the end of a chromosome that is responsible for protecting the chromosome and is also involved with the lifespan of that cell.
