BTE101 assignment--Telomere and telomerase


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BTE101 assignment on Telomere and telomerase
For Professor Naiyyum Choudhury's class

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BTE101 assignment--Telomere and telomerase

  1. 1. Save Plants! Don’t Print! Go Green! June 26, 2011 BTE 101 Introduction to Biotechnology and Genetic Engineering Professor Naiyyum Choudhury Assignment 01: Telomere & Telomerase Done by: Samiya Yesmin I.D. 11304043 1 Telomere & Telomerase
  2. 2. Save Plants! Don’t Print! Go Green! June 26, 2011 What is a Telomere? A telomere is a region of repetitive DNA sequence at the end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. The telomere regions deter the degradation of genes near the ends of chromosomes by allowing for the shortening of chromosome ends, which necessarily occurs during chromosome replication. This is very important as otherwise viable information from the chromosomes would be lost resulting in the formation of unviable cells later thus changing the DNA. What is a Telomerase? Telomerase is an enzyme that adds DNA sequence repeats ("TTAGGG" in all vertebrates) to the 3' end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes. This region of repeated nucleotide called telomeres contains non-coding DNA material and prevents constant loss of important DNA from chromosome ends. As a result, every time the chromosome is copied only 100-200 nucleotides are lost, which causes no damage to the organism's DNA. Telomerase is a reverse transcriptase that carries its own RNA molecule, which is used as a template when it elongates telomeres, which are shortened after each replication cycle. 2 Telomere & Telomerase
  3. 3. Save Plants! Don’t Print! Go Green! June 26, 2011 How telomerase works? 1. During cell division, the DNA helix unwinds and separates to replicate. RNA primers attach to both the now separated strands of the helix. 2. Both strands are then synthesized by DNA polymerase. 3. Leading strand (3'-5') is completely synthesized. 4. But lagging (5'-3') has a gap left at 3'end. This would shorten the chromosomes after each round of cell division, eventually leading to a loss of information making new cells unviable. 5. Enter Telomerase! Telomerase contains: 1. RNA molecule template 2. Reverse transcriptase extend 3' end using the template. 6. This leaves behind six base tandom repeats called telomeres. 3 Telomere & Telomerase
  4. 4. Save Plants! Don’t Print! Go Green! June 26, 2011 7. The process is completed by normal lagging strand synthesis by DNA polymerase. 8. Thus protecting the genome from potential loss of information. Telomere and Aging Cellular aging is the process by which a cell becomes old and dies. It is due to the shortening of chromosomal telomeres to the point that the chromosome reaches a critical length. Cellular aging is analogous to a wind up clock. If the clock stays wound, a cell becomes immortal and constantly produces new cells. If the clock winds down, the cell stops producing new cells and dies. Our cells are constantly aging. Being able to make the body's cells live forever certainly creates some exciting possibilities. Telomerase research could therefore yield important discoveries related to the aging process. This also raises the question of why longer telomeres are not selected for to ameliorate these effects. A prominent explanation suggests that inheriting longer telomeres would cause increased cancer rates (e.g. Weinstein and Ciszek, 2002). However, a recent literature review and analysis suggests this is unlikely, because shorter telomeres and telomerase inactivation is more often associated with increased cancer rates, and the mortality from cancer occurs late in life when the force of natural selection is very low Therefore as the body ages our cells lose some of their ability to regenerate and to perform the functions they were designed to perform. Our hair turns gray, eyesight and hearing fade and even our organs begin to deteriorate. Most scientists will tell you that the aging process is brought about by changes in the proteins, lipids and nucleic acids such as DNA and RNA that make up our cellular structure. This aging process can be slowed down by introducing certain changes to aging cells, and when those changes are introduced, the cells rejuvenate to the point that they function as if they were much younger. This is the tragedy that occurs on everyone's 25th birthday. That is from this point on every time their cells replicate, the telomerase enzymes, that translate the information required to replicate an identical youthful cell, are shortened--creating a loss in translation scenario that which leads to cellular damage and ultimate cellular death a.k.a. Aging! Telomerase is a new theory of aging that holds many promising possibilities for the field of antiaging medicine. It has been discovered that Telomerase enzymes are sequences of nucleic acids 4 Telomere & Telomerase
  5. 5. Save Plants! Don’t Print! Go Green! June 26, 2011 extending from the ends of our chromosomes and acting to maintain their integrity. Thus no loss in translation and you stay youthful!  Here's the scientific basis behind this amazing discovery: The role of telomerase appears to be manipulating the life of the cell by presiding over the mechanism that controls how long the cell lives. Some cancer researchers believe that the creation of a targeted telomerase inhibitor may actually be able to stop a cancer cell's ability to divide--thus stopping the spread of cancer. It is even widely believed that specialized telomerase enzymes might actually be able to convert cancer cells back into normal cells! Despite the fact there is continuous research going on in the field of anti-aging, there has yet to be a consensus on the actual cause of cellular deterioration that account for the aging process. Once of the most confounding issues faced by researchers is the fact that the aging process is not predictable or uniform across all of humanity. Each of us age differently based upon our genetic makeup, degree of stress, dietary habits, environment, etc. As a matter of fact the only thing all of us share in common is the fact that we are all aging and all our cells will eventually give out. Some have actually taken the steps to extract active telomerase enzymes from live cultures in order to create a supplement that brings science reality into the room NOW—the modern Philosopher’s Stone!! RENEUVE™ is such a paradigm-shifting product. It delivers the exact enzymes that degrade past your 25th birthday. Thus you won’t have shorter telomeres. And your cells can remain youthful! It's just like bringing a dying plant back to life with just some water and fertilizer. RENEUVE™ is the "water and fertilizer" that your cells need to flourish. 5 Telomere & Telomerase
  6. 6. Save Plants! Don’t Print! Go Green! June 26, 2011 Although this is just one of the first of its kind… and this science is relatively new, but we could perhaps someday gain immortality!! :D Anything could be possible!! Science is the key to hope! Sources: 6 Telomere & Telomerase