"In the film "The president and Miss Wade," Michael Douglas was a U.S. president who had just wrapped up with Annette Bening. When she arrived at the scene to be put to bed for the first time the president will take an attack of nerves, typically male , and he points out that "the expectations that she may have, taking into note that he is the most powerful man in the world, then remember that this is only a political and distinction ... "
And this is creating great expectations often result in disappointment. It happens in books, films and even the people that maybe you should appreciate the virtues if not been discussed much. Well I would say the same thing happened yesterday at NASA.
really created many expectations. Monday convened a press conference to make an announcement "of great importance in the search for extraterrestrial life." Home! NASA says that this suggests that they have found at least one alien organism. Maybe we have not contacted little green men, but simply because extraterrestrial bacteria would be a bomb.
But when it came time to decide, with press conference broadcast live over the Internet, the news caused some disappointment. A pity, because the discovery is history. Will change the textbooks and we look at life differently since yesterday. But with expectations raised, it seems that something is a flop. I think they should have announced it with less fuss.
What we have discovered extraterrestrial bacteria is not (as some news is announced), but one here on Earth. A bacterium called GFAJ-1 growing in a lake California and have a special never seen until now: "You can replace the phosphorus by arsenic in their biomolecules. It seems a great pump information, right? Well believe me, it is. But it is still a bomb at very academic and requires some explanation. It is the discovery of an alien as expected and NASA seemed to suggest.
When one examines the life of the things that make grace is that despite the vast differences that exist in shapes, sizes and lifestyles, the chemical basis that all organisms on Earth is almost same. From whales to bacteria, chemical reactions that occur are the same or very similar. The DNA encoded with the same genetic code, is the molecule that we use to store genetic information. The proteins made with the same amino acids, are the pieces that build the bodies. Burn the sugars for energy and as a specialized molecules called ATP is all we use to transfer energy.
All this range is achieved by combining a few atoms. Although there are many chemicals available on nature, life as we know (knew ) is based on six types of atoms. Students used the word CHONPS to remember that life is based on carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. You will notice that P corresponds to phosphorus because P is its chemical symbol (for Phosphorus).
Phosphorus is an essential and part of the DNA, RNA, the ATP and many biological processes. It is very common to be used as "switch" and there are proteins that are inactive and start running when you need it simply sticking a phosphate group. Therefore phosphate fertilizers are important. The cells need phosphorus, usually in the form phosphate, to survive.
Well you have found a bacterium that can survive using arsenic instead of phosphorus. Not only can survive in a place with arsenic. This bacteria can use arsenic instead of phosphorus to make things like DNA. Instead of ATP (adenosine triphosphate to) make ATAs (for adenosine triarseniat). We had never seen a DNA molecule that was different from the others. But now we have found one that works with a different chemical.
Then come the details. The bacteria used preferably phosphorus, but only if Arsenic is thus incorporates. This means that you have a metabolism, enzymes, very private. Arsenic is a poison for us because it closely resembles the phosphorus. If we eat, can take its place, but then makes our biochemical machinery to stop working. Instead, these bacteria have found ways to leave it, incorporate it and keep working. Therefore, if we find extraterrestrial life, until yesterday, a place without the phosphorus and arsenic should not considered promising. But arsenic just joining the elements that can sustain life. We have a whole front new chemistry of life, with the hitherto only speculated.
As a biologist I find it extraordinary. Publishers of books on science can begin to rewrite some chapters. This has many implications for both life out of space. I have no doubt that the discovery could be the year. But how NASA made the announcement was perhaps a little too excessive. That day will eventually find a body alien? "
0 comments:
Post a Comment