Theories of Aging: Telomeres Outbreak
Why do we Age?
Telomeres are the ends of our chromosomes much like the ends of our shoe laces. When the tips of our shoe laces wear away or fray, it is much harder to tie. This is the same concept behindtelomeres.
DNA Polymerase, helicase, ligase, and numerous other enzymes work to replicate, and transcribe DNA within the nucleus of all cells through Mitosis. All DNA that is translated is wrapped into 8 protein histomes and one stabeliser protein and coiled into a chromosome with repeating nuclear bases at the ends to hold the ends of the chromosome tips together.
The problem comes when the telomeres are worn off through years of replication. Many of our cells do not actually divide and play a very important role in sustaining life. When the telomeres are worm away, the cell does not work efficiently and may die. The cells that do divide will not do so efficiently. DNA Polymerase copies the complementary bases in the replication fork of the DNA as helicase untwists and unwinds it. They will work as far as the telomeres. Without the telomeres, DNA polymerase may slide right off the end, or it may not begin the replication process at all. DNA that are produced do not work as efficiently. Without replication, cells can not be replenished leading to a slow healing process. In addiction, mutations may occur during the replication phase that leads to cancers or other potentially fatal diseases.
There are However Counter-Arguments to the telomere theory. While it is clear that the telomeres have an effect on aging, it isn't the only cause. Many animals have very short telomeres, yet live a long time and many with very long telomeres yet live only a mere few days. Fruit flies have very long telomeres, yet they live only a few weeks which shows that there is much more to aging than only the length of our telomeres
Growth and Longevity
Animals who never stop growing tend to live longer than those who stop. The practice of this phenomenon is very well known and seen everywhere in nature. Turtles live to be over 200 years old; the sturgeon fish over 300 years. Both of these species never stop growing. Looking in nature, we see that nearly all animals who stop growing never make it past 100. Humans are no exception. The only reason a few of us are able to make it past 100 is because of modern technology. I believe a sturgeon fish in perfect living conditions may live as long as trees, which brings me to my next example. Trees live well over 1000 years old. They are the perfect example of the power of growth.
Intelligence and Longevity
There is a corrolation in nature that smarter animals tend to live longer than those who are rather dumb (with a few exceptions). Compare the avg life span of these animals:
- Humans, Dogs, Cats, Whales, Dolphins
- Most Fish, Most Insects, Most Jellyfish.......most animals.
There is one animal that boggles the mind - Turritopsis nutricula, aka the immortal jelly fish. This miraculous jellyfish lives FOREVER (as long as it has ample food, and avoid being ingested). It survives by turning back into its polyp state so in other words, it is the phoenix of the ocean.
Most of us have heard of free radicals and antioxidants, but have no clue what they are. It is plastered all over bottles of OJ and vitamin bottles. Free radicals are unpaired atoms. The free radical most produced is Oxygen. Basic chemistry shows that oxygen is looking for something to bind to. There is no such thing as oxygen by itself in the air your breath - only O2. So, the oxygen free radical binds to cells, nucleic acids, or whatever is around it causing damage making all our metabolic processes run inefficiently through years of exposure.
Antioxidants are essentially what the word suggests. It gets rid of free radicals by giving it something to bind to. A big one is Vitamin C, but any nutrient which binds to free radicals are antioxidants.
This theory works under the premise that through evolution, our bodies are so caught up with repairing short term problems such as a malaria outbreak (in Africa, the gene for hemophilia which causes sickle cells is much more common than in other parts of the world because those who have hemophilia can't get malaria) that it neglects long-term problems such as aging itself.
Have you noticed that humans no matter how we take care of ourselves, never get past the 100's. Someone who eats junk food and sits on the couch all day may live as long as someone who only chooses the healthiest foods and exercises daily and live the same amount of time. This lead to the theory that we are bound by our genes like a time-bomb. Furthermore, scientists are able to map genes as well as recognize who has a high possibility of getting certain diseases like cancers.
Another isolated gene associated with aging is the foxo gene. It turns out in a study that nearly all people over the age of 100 and are still as active as when they are 20 have multiple sets of the foxo gene. It isn't that exercise is making them healthy, it is because this gene allows them to feel young even when old. This leads me to my next theory of aging.
Damage to the Body Repair System
Remember my discussion about the foxo gene? Well, this gene happens to deal with gene repair. DNA replication, transcription, and even translation (at the ribosomes) often leads to mistakes such as an adenine paired with a cytosine instead of the correct pair of adenine-thymine. This single base pair may lead to in correct replication that leads to diseases like cancers, dysfunctional production of immune cells like B-cells and T-Cells, or if insulin, then Diabetes. The body repair system works by trashing these dysfunctional cells by causing the cell to set off a flag on its cell membrane to either be engulfed by Macrophages (often called the junk eater much like Pacman) or release its lysosomes which contains digestive enzymes that destroys the cell in a process called apoptosis (cell death). When the cell repair system is damaged or a damaged DNA gets past the repair system, these mistakes accumulate are results in the effect of aging.
Fortunately, this system is very efficient. This process contributes to aging but is in no way the only cause. People who are over 100 may have a repair system that is in perfect order, yet they are old which shows that it doesn't have total impact on aging.
Well, here are a few theories I've learnt about aging. I hope you had fun reading.
Please favorite this article, tell your friends, and spread awareness so that we may have more dedicated scientists who strive to cure the underlying cause of death, aging.
Have a Nice Day!
~ Nathaniel Zhu (http://www.youtube.com/epicathiest)