Posted on 11/16/2005 3:40:35 AM PST by snarks_when_bored
* 14:02 15 November 2005
* NewScientist.com news service
* Gaia Vince
A new microscope sensitive enough to track the real-time motion of a single protein, right down to the scale of its individual atoms, has revealed how genes are copied from DNA – a process essential to life.
The novel device allows users to achieve the highest-resolution measurements ever, equivalent to the diameter of a single hydrogen atom, says Steven Block, who designed it with colleagues at Stanford University in California.
Block was able to use the microscope to track a molecule of DNA from an E.coli bacterium, settling a long-standing scientific debate about the precise method in which genetic material is copied for use.
The molecular double-helix of DNA resembles a twisted ladder consisting of two strands connected by “rungs” called bases. The bases, which are known by the abbreviations A, T, G and C, encode genetic information, and the sequence in which they appear “spell out” different genes.
Every time a new protein is made, the genetic information for that protein must first be transcribed from its DNA blueprint. The transcriber, an enzyme called RNA polymerase (RNAP), latches on to the DNA ladder and pulls a small section apart lengthwise. As it works its way down the section of DNA, RNAP copies the sequence of bases and builds a complementary strand of RNA – the first step in a new protein.
“For years, people have known that RNA is made up one base at a time,” Block says. “But that has left open the question of whether the RNAP enzyme actually climbs up the DNA ladder one rung at a time, or does it move instead in chunks – for example, does it add three bases, then jump along and add another three bases.
Light and helium
In order to settle the question, the researchers designed equipment that was able to very accurately monitor the movements of a single DNA molecule.
Block chemically bonded one end of the DNA length to a glass bead. The bead was just 1 micrometre across, a thousand times the length of the DNA molecule and, crucially, a billion times its volume. He then bonded the RNAP enzyme to another bead. Both beads were placed in a watery substrate on a microscope slide.
Using mirrors, he then focused two infrared laser beams down onto each bead. Because the glass bead was in water, there was a refractive (optical density) difference between the glass and water, which caused the laser to bend and focus the light so that Block knew exactly where each bead was.
But in dealing with such small objects, he could not afford any of the normal wobbles in the light that occur when the photons have to pass through different densities of air at differing temperatures. So, he encased the whole microscope in a box containing helium. Helium has a very low refractive index so, even if temperature fluctuations occurred, the effect would be too small to matter.
One by one
The group then manipulated one of the glass beads until the RNAP latched on to a rung on the DNA molecule. As the enzyme moved along the bases, it tugged the glass bead it was bonded too, moving the two beads toward each together. The RNAP jerked along the DNA, pausing between jerks to churn out RNA transcribed bases. It was by precisely measuring the lengths of the jerks that Block determined how many bases it transcribed each time.
“The RNAP climbs the DNA ladder one base pair at a time – that is probably the right answer,” he says.
“It’s a very neat system – amazing to be able see molecular details and work out how DNA is transcribed for the first time,” said Justin Molloy, who has pioneered similar work at the National Institute for Medical Research, London. “It’s pretty incredible. You would never have believed it could be possible 10 years ago.”
Journal reference: Nature (DOI: 10.1038/nature04268)
We can jump in here, and mess up THIS thread.
http://www.freerepublic.com/focus/f-news/1525082/posts?page=8#8
After all; they DID say the code word!
I am a medieval man. Full Disclosure: Disco mode.
Math is abstract. Science attempts to describe reality.
Mathematics is reality, while your version of science is just a pitiful human attempt to describe it...
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* Posted by Dimensio to Sir Francis Dashwood
I am here to correct the logical fallacies and factual errors often presented by creationists.
That is just my point, neither the so-called Big Bang or evolution theories are proven truth...
Just because you claim they are by your religious faith in them does not lessen the validity my criticism. I'm not an ecumenical or an orthodox atheist. Nothing is sacred to me. Your appeal to false authority is categorically no more true than what you accuse creationists of doing...
Your only purpose here is to advance a religious attack on the godists, your own holy war. This crusade is as illogical as is your lack of evidence in defense of the Big Bang and the evolution of human beings.
The “missing link” is missing still, as is any logic to your arguments. (Don't try to tell me Louis Leaky didn't spend decades looking for the “missing link” when he found Homo habilis and Zinjanthropus either.)
Your version of logic isn't even close to Boolean logic, categorical logic or prepositional logic...
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Both of you are attempting to “cloud the issue” with ancillary and unrelated topics...
The original article that began this thread, one poster pointed out, contains a statement by the author about the “design” of DNA. Logic suggests that would mean some sort of designer, wouldn't it? Not that I would agree, but I do see the fallacy embedded in the story, as I see the fallacies promoted with unproven theories as the sole basis for their use as the only course of research.
What the both of you are doing makes about as much sense as the idiot Pax Macian on the drug threads trying to tell an atheist like me that God wants people to be drug addicts and then giving me long Biblical litanies that have nothing to do with drugs...
You will find some here altogether too serious for simple attempts at humour. The rest of us appreciate a bit of humour here or there; puns of course being the pinnacle of said humour.
All I ask is that your puns remain on the less obscure side, so even the densest among us (primarily me) can enjoy them.
I appreciate your compliment--this is balm to my wounds after being called "mostly harmless" by CarolinaGuitarman. (See also the entry on Earth from the HitchHikers Guide to the Galaxy.)
All I ask is that your puns remain on the less obscure side, so even the densest among us (primarily me) can enjoy them.
We aim to please.
My adjurement to an earlier poster to "Play Fair" was a pun on "Playfair's theorem" from Euclidean geometry, after the poster had mentioned that a**2 + b**2 = c**2 does not hold in some curvilinear coordinate systems. (Playfair's theorem goes along with sum of angles of triangle being 180 degres goes along with ...)
Didja like the mosquito limerick?
:^)
The Canadian judge gives a 5.6
Ouch!
I LOL. But I thought DDT was illegal?
Here's another version.
A mosquito cried out in pain:
"A chemist has poisoned my brain!"
The cause of his sorrow
was para-dichlorodiphenyltrichloroethane
My daughter told me this one:
Water is composed of two gins, Oxygin and Hydrogin.
Oxygin is pure gin. Hydrogin is gin and water.
I think you have that backwards ...
Science can't speak of ethics and morality since they are religious based or based on unscientific personal biases.
An atheist scientist telling another atheist scientist that it is wrong and a lie to falsify data is speaking gibberish since science can not speak of moral truth. After all, while the scientist can be kicked out of the academy for falsifying data, there is no other moral judgment that can be supplied to brand the man an immoral liar...since science can not make absolute moral judgments!
Perhaps science SHOULD stay out of churches and churches OUT of science. Science can go make bombs...church folk should go fashion constitutions...like the constitution that founded this country 220 odd years ago.
Not a lot of scientists around when the Bill of Rights was established...but there were a bunch of religiously minded folk who were.(and yes I know some were Deists and atheists. but most of them were very well versed in Christian theology and history as well...and horror of horrors..Baptists, methodists and congregationalists as well).
So scientists go ahead and play with your trinkets and fossils and try to sell the rest of us on how you think the world began, and when the world is smoldering from the effects of the amorality that such materialist thought has wrought, it will be Christians trying to put civilization back together(the meek who have just inherited the Earth).
Science can tell how things are put together but it cannot teach how men should LIVE TOGETHER! Science cannot create rights and priviledges that men of Liberty should enjoy, it is the shared consenses of Religion and Morality that undergird our country's freedoms!
If our world were to be smoldering in the near future, who would you call for the tools you need to survive--arrowheads, spears, fire? Would you call the priests or the archaeologists?
You would probably end up as a vegetarian, while you lasted (vegetarian--that's the Indian word for "bad hunter").
It seems that these tools you mentioned were developed by folk who had a rudimentary religious world view even thousands of years(for sake of the arguement) before Oppenheimer quoted a Hindi verse as he watched the Atomic bomb flash into existence"I have become Vishnu, the destroyer or worlds". No scientists running around thousands of years ago...just religious folk...or wannabe's,or lipservice atheists in fear of losing their heads.
Science can't create a civilization...at best it exists as civilization's servant; at worst it becomes the club of tyrants who scurge the virtuous and powerless into slvery with it!
Several reading assignments for you:
C.P. Snow, The Search
C.S. Lews, The Abolition of Man
D.L. Sayers,Gaudy Night
Cheers!
You would probably end up as a vegetarian, while you lasted (vegetarian--that's the Indian word for "bad hunter").
"The only tool you own is a set of toenail clippers. Whereas Steve has a wide assortment of both jacks and winches. Steve's children play with jacks and winches. Steve has every kind of tool he'll ever need for anything, right in his truck. If the world economy ever collapses, and mankind regresses to a primitive state, guys like Steve will be living in sturdy, safe shelters that they built with their own hands, eating food that they grew or caught. Whereas guys like you will be passing through the digestive systems of wolves."
--Dave Barry's Complete Guide to Guys
Cheers!
I've read the Abolition of Man, where CS Lewis writes of the creation of "Men without Chests" by Britain's "modern school curricula...he is very scathing in his assessment of where modern materialism is going "We have created men who think critically with their brains and act sensually with their bodies(the exact quote may be off a bit but I know I am quoting the substance), but are devoid of age old virtue...we have created "en without Chests"
Many of them have been proven true (i.e., the earth is not flat).
But since you flat earth types will falsely claim that is not so, you cannot also logically claim the creationist theory a falsehood, as both evolutionary theory and creation theory “appeal to false authority,” an informal fallacy in logic.
This makes neither of them any more valid than the other, nor are either of them any more valid than the zany theory life came to this planet via extra terrestrials.
Evolution is nothing more than a religious science you defend.
So, I'm a heretic... As I said, I am not an orthodox atheist, nor am I an ecumenical atheist (there is no such thing).
1) Uniformity of ethics across cultures
2) The idea that the reputation of those attacking morality as more intellectual was an illusion.
In other words, there is a difference between knowledge and wisdon; the old quote about "the heart has its reasons, of which reason knows nothing"; the difference between connaitre and savoir (sorry about the missing circumflex...); etc.
Try The Search and Gaudy Night too. Things aren't always as clear in practice as they are in FR bull sessions. :-)
Cheers!
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