Why do we age and not live forever? Is immortality possible and does it exists?
Phoenix, Marvel Comics
Egyptian Phoenix (Bennu)
Chinese Phoenix (Fenghuang)
Most of us would think of a super human being or a god when we think of immortality. The media has portrayed immortality in a variety of ways; from a entity that ages but can’t die from physical injury or old age or one that stops aging at a particular stage and stays that way forever and cannot die no matter what. One popular immortal mythical creature portrayed in the media and many cultures around the world is the Phoenix; once it "dies" it rises from its ashes and lives again a new life. In either interpretations of immortality, it involves something supernatural. Although there are many ways to interpret immortality, I will focus on it at a cellular level; a cell that cannot die from aging but can die from other things such as starvation, physical trauma or pathogens (disease causing microbe).
First of all, why do we age? One major explanation or theory to why we age is that the telomeres in our cells shorten whenever it divides. Each one of our cells has DNA. Telomeres are DNA themselves, but are located at the end of the entire DNA molecule, or chromosome, and are composed of repeated sequences (repeated sequences meaning repeating in any of the 4 components of DNA: A, T, G, and C in a particular order, for instance in humans it is many repeats of just TTAGGG over and over again). The main purpose of telomeres is to protect our genes, our genetic information, from cleavage damage from cell division or other processes; when genes are destroyed they become cancerous or are unable to make useful proteins needed in life.
Cell division is important for growth, injury repair and many other things; whenever a cell divides its telomere gets cut and so does a portion of the lifetime; our cells that makes us age and therefore we age. When a cell divides, it needs to replicate its DNA so it can pass it on to its progeny cells, since the telomeres in DNA gets shorten during this process both progeny cells get a shorter DNA than their parent cell and therefore a shorter life. This is the reason why telomeres are at the end of the DNA so that it gets destroyed instead of DNA that stores useful information.
Telomeres indicated by red regions in these chromosomes
If our cell’s DNA did not have telomeres, then it simply would not divide or our genes would be destroyed after only a couple divisions. According to the Hayflick Limit, a theory that states the number of times a cell can divide before it dies or stops dividing, a human cell can divide 50-70 times before it stops and dies. Basically, when the telomeres are gone and done with, so is the cell. It is not clear to why our cells cannot retain the same telomere length we were born with and why it shortens after each cell division but we do know that is it not from a damaging process. As Dr. Bill Andrew describes it “it’s not a wear and tear mechanism, it’s simply due to the fact that our cells lack the ability to replicate the very ends of the chromosomes and is a passive process.” Amazingly, your age can be estimated just by looking at the telomere lengths in your DNA. One way in which the cell reverses this process is by an enzyme called telomerase, which elongates the ends of telomeres that have gotten shorter. However, as the cell gets older the activity of telomerase weakens.
So are there living things that are immune from the damaging processes of aging and can live forever (can’t die from old age)? Yes.
Cancer cells are a prime example of immortal living entities in biology, and yes they really are immortal especially if kept in a controlled laboratory environment where nutrients are constantly replaced, waste is constantly removed, and are kept from outside sources that can cause them trauma. Okay, so there's not supernatural stuff happening here, but it's still pretty damn amazing the fact that these cells can never age. The simple reason why cancer cells are immortal is because their telomeres don’t get shorten; they always have an overabundant supply of active telomerase. They can divide for an infinite number of times, defying the Hayflick Limit, never age and can live forever if they don’t get fatally injured or starve to death. Not only are cancer cells immortal but they also divide rapidly. This is why they cause tumors, because they don’t die from aging and just keep on dividing infinitely to create a huge blobby mass.
One famous line of immortal cells used in research is the HeLa Cells, named after Henrietta Lacks who is the source of these cells. She died from cervical cancer in 1951; the cancer cells obtained from her, without her permission, have been dividing since her death and used in research labs all over the world. What makes these cells and other cancer cells more amazing is that they can survive outside of their source organism, unlike most normal cells that die shortly when taken out of the body.
The immortal HeLa Cells
Other examples of cells that don't show signs aging and can be immortal are sex cells and bacteria. In sex cells, it is almost the same biology behind cancer cells, their telomeres don't shorten due to active telomerase; however, I believe the mechanisms behind why these cells don't age is less known than cancer cells. In bacteria it is much different; MANY, BUT NOT ALL, bacteria have a single circular chromosome. When bacteria divide they replicate their entire chromosome and if there are no errors in the process, there is no loss of genetic material.
Egg and sperm
Bacteria
With the discovery and knowledge of telomeres and telomerase there are a lot of crazy things certain scientists are probably trying to do (this alone can be the topic of another post itself). Of course, one way benefit of this knowledge would be to treat cancer. In studies done with mice with cancer, taking away telomerase from the cancer cells caused the death of them. Next for us is to find a way to destroy tolemerase in human cancer cells. There's also this idea of how living forever may be possible. However; when I asked many of my friends if they wanted to live forever many of them said no.
I write extremely LONG posts; I will be posting more shorter post starting from now. Anyways, with all my talk about genes and genetic engineering, I thought this was a funny video parody of Disney and what I've been talking about in my previous posts. The video is about how geneticists grow human beings in a lab with desirable traits of a super star. Imagine if there really were known genes that gave traits of great singing, dancing, and looking good; I can see some wanting their babies to be grown in these labs and, most likely, a lot of people banning the idea. Although a person may not be born with these traits, in a way, I do think stars in real life are "engineered" or instructed by their agents to act or look a certain way to be more famous and rich, which is a bit sad. Anyways, enjoy the video!
I failed a very important test recently (no it wasn’t school or textbook related) and so I just want to devote this post to a free write of my feelings about blogging and any other thoughts I have compiled in the past few days. So failing this test has put me in a very despairing state. I’ve been ignoring all my friends that want to go play Tennis and do other fun things; the strange thing is that Tennis or any other physical outdoor activity is very therapeutic for me and I don’t even want to do any of them right now. I have been doing nothing but sit in front of the computer and eat loads and loads of junk food, particularly Twinkies. I’m really mad at myself for caving in under pressure and whenever I’m mad with myself and feel unworthy, to the point where I don’t want to do anything, I distant myself from the world and the people I know for a good amount of time. For me, during these times, I rather be alone so I can re-evaluate my life.
Why this post and not a post about Microbiology? Well, first off, I don’t really want to talk about those things right now and I think it’s important to just take a breather when you need it and do some self-reflection.
Anyways one thing I have been doing a lot the past few days, besides indulging in s***** food is reading on the net; random subjects from articles on Yahoo and mostly from other Blogs and I don’t really know why this was the only thing I’ve been doing. I was able to do this because I actually deactivated my Facebook and accounts on other social network sites. By doing that and reading, I realized that there is really not a lot of time spent on writing these days and expressing oneself or analyzing problems thoughtfully. It’s a lot of one sentence or one word statuses, watching videos on Youtube only to leave a f*** *** or other 4 letter curse words on comments of videos you don’t like, which I must admit I’m guilty of from time to time. I even came across a Blog that discussed about how Blogs are becoming extinct now since it’s only older folks that are doing it and once they are gone so will Blogs.
At first, this was just a class requirement for a class that I didn’t want to be in; another boring and pointless activity. Initially, I was just going to post about biology issues, sound like a textbook with bare minimum lengths and be done with it because I thought Blogging was stupid. After reading other people’s Blogs, from classmates and other strangers on the internet, I really feel like Blogging is a form of an open diary where you post issues about your topic, of course, but also incorporate a bit of your thoughts. Besides expression, I realized that blogs can be a form of self-discovery and can be quite calming at times, something that is not done much with people these days. I bring up expression, because if we were to do essays in this class I don't think we would be able to do much of it due to confines of grading, not incorporating videos and pictures and writing about something we don't like.
Of course, at this point, I haven’t produced a lot of posts… well at least the amount required. However; I do spend a lot of time thinking about what my next topic should be. I also go back to my previous posts occasionally to read and work on the flow and correct any errors. Most importantly, I really try my best to research on my topic, refresh my memory so that I can make it easy to for people to comprehend and also thought provoking; try to avoid any fancy or complicated scientific terms so that it’s more relatable and less confusing, and steer away from many of the complicated processes or at least break it down straight to the point.
As I hinted on before, I was going to explain everything with my current knowledge and write without much thought; but after the class evaluations and everything it wasn’t going to happen anymore, which I’m kind of glad. By doing research on things I think I know about, I discover more interesting things and I feel like I want to explain it more with care as opposed to just randomly talking about it like nothing. In a way it made me ponder upon certain issues deeper instead of just recalling the scientific facts I’ve memorized about them.
I don’t know how long this interest will allow me to Blog, if any, after this class but at this moment I think I’m getting the hang of Blogs. I realize that perhaps writing does have some benefits besides for school work. Anyways, I'm a bit glad I took some time out to do some self-reflection and evaluation.
In my last post I gave a brief explanation on what genes are and touched up a bit on bioengineering and gene alteration in organisms; these organisms that result from such applications are called genetically modified organisms (GM or GMO) or transgenic. In most cases with GMOs, their original genes are not altered themselves but they have genes with desirable traits injected into their DNA. This application is used on a variety of organisms and the possibilities seem to be growing as fast as other technologies. Here we go over some of the uses of genetic engineering.
PLANTS
Plants, crops, fruits and veggies are among the most genetically modified organism today, especially since food is perhaps the most important commodity to us. GM produce grows faster and have a longer shelf life, this is very beneficial in countries where food source is scarce. This may also be helpful one day to help mass produce plants used for biofuels. The genes of desert plants, such as a cactus, can be inserted into a crop, a tomato, so that it can grow in areas that are either too dry or too hot for a normal tomato. GM plants can also be engineered to resist pests, herbicides. Even more interesting is that plants can be made to produce plastics, and human tissue. Who knows what other crazy things scientists will do with plants; bizarre colored fruits to weirdly shaped ones, to one tasting like another!
ANIMALS
Pets are also commonly engineered in a way to look more attractive or exotic to increase sales. One of the first genetically modified pet is the GloFish; which are zebrafishes made to have a variety of vibrant neon colors. Besides looks and appeal, this technology is making it possible for people that can't have certain pets be able to. Back in 2006, a company was able to produce cats and dogs that produced little (hypoallergenic) to no allergens. Though probably much more expensive, this may be a blessing for those who suffer from allergies from cats and dogs that really wants one. Of course, I don't advocate much of this, maybe the hypoallergenic cats and dogs a little, but if you are unhappy about GM animals perhaps you should report it to PETA.
Of the organisms I've mentioned, bacteria are the most easiest to genetically manipulate due to their simple structures and fast reproduction times. Also, many activists or other anti-GMO individuals wouldn't really care about bacteria being altered compared to plants, animals or "higher organisms". Most of the genetically engineered bacteria today are used to produce pharmaceutical drugs, vitamins used in multi-vitamin pills, and essential enzymes or proteins such as insulin. Others are made to be more efficient at producing certain foods, mainly in the dairy industry. As I mentioned in my other post, scientists have made glowing bacteria. I guess one purpose of this is BioArt, something I stumbled across while looking for links for this post. BioArt, as it's name implies, is artwork made out of life. Interesting.
