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)
I did not say there is one. I said there may be one. Unlike you, I am not inclined to rule things out when it comes to the practice of science.
It's a classic example of a tautology. Unfortunately for you, that isn't science, that's just your feeling.
On the contrary, tautologies are of value both logically and scientifically. They have little to do with intuition, or feelings. But even intuition and feelings have a place in science. Those who deny it build themselves a weak soapbox. It is you who are operating with a false notion of science, both in regard to its practice and limitations.
Welcome to the Owly Old Fart club.
placemarker
It is not as though the notion of "no intelligent designer" is falsifiable either. One can trump anything seen by saying, "Nature did it through unguided, undesigned processes." If you want falsibilty and testability alone to be the standard by which anything is rendered scientific, then what's good for the goose is good for the gander, baby.
If there is a.) such thing as intelligence, and b.) such thing as design, then there is no reason science cannot at some point reasonably test for it and detect it. You stretch science to the point of a gross caricature of reason in suggesting there is "no evidence for intelligent design" when so much matter is organized to carry out purposeful function on a scale both micro and macroscopic.
You've indulged your hatred of God to the point of insanity, and it is unbecoming.
I the designer is capable of creating a given artifact he/she/it can easily emulate nature. There's the rub. If you, as most IDIsts are wont to do, create a mutually exclusive and exhaustive dichotomy of designed or natural, the ability to emulate pretty much makes it impossible to determine an artifact's true origin.
Fester, Fester, Fester...
Everytime you post one of your absurdities, I think "Wow, he can't top this one!" And then you post again...
Sounds like he read and misunderstood something by P. Johnson.
[Liberal Classic:] No, I'm going to back him up on this. Behe said, under oath, quote, "the designer is God" unquote.
[r9etb:] Fine. Give me the quote, "transcript," unquote, so that we can see his exact words, in context, rather than taking it on your say-so. Not too much to ask, eh?
Not at all:
Q. Well, people have asked you your opinion as to who you believe the designer is, is that correct?
A. That is right.
Q. Has science answered that question?
A. No, science has not done so.
Q. And I believe you have answered on occasion that you believe the designer is God, is that correct?
A. Yes, that's correct.-- Michael Behe direct examination by attorney Robert Muise, in trial transcript of Kitzmiller v Dover Area School District, October 17, 2005, Morning Session, pages 94-95.
Q. [...reading from Behe's own book:] "Thus, in my judgment it is implausible that the designer is a natural entity." You don t absolutely rule it out, but you re not taking it very seriously, are you?
A. Well, I ve said that quite a number of times. I think I said that at the beginning of my testimony yesterday, that I think in fact from -- from other perspectives, that the designer is in fact God.-- Michael Behe cross-examination by attorney Eric Rothschild, in trial transcript of Kitzmiller v Dover Area School District, October 18, 2005, Afternoon Session, page 100.
Q. Now, you ve said in your testimony today and yesterday you personally believe the designer is God.
A. Yes.
Q. And in this article in fact you say for purposes of the discussion I m going to assume the supernatural entity is God, right?
A. Yes.-- Michael Behe cross-examination by attorney Eric Rothschild, in trial transcript of Kitzmiller v Dover Area School District, October 18, 2005, Afternoon Session, page 103.
Science is greater than testable, or falsifiable claims. Testability ands faslsifiability are not the only attributes that cause something to be scientific. Indeed, something can be scientifically true and accurate without being either testable or falsifiable. Obviously those who would like to hold ID up to their own idea of a scientific standard are disappointed in this truth, but it is a truth they must face nonetheless.
My faith the the flatulence of a cosmic deity as causative of anything remotely ordered extends only as far as your own existence and subsequent communications in my direction. Please try to contain the same.
I've made a few beautiful and good things in my time -- am I therefore God?
No, but your explanation for its origin *is* based on a feeling.
I should expect as much from someone who would deny science the full use of human reason.
Looks like you've twisted your logical panties into a little wad. Relax. God created the heavens and the earth. He sustains them to this very moment. It's all real, it's all scientific, it's all designed, and it's all under control.
So when you see an automobile and assume it is designed, it is just because you have a "feeling?" Baloney.
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