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)
You've fashioned your own definition of miracle. "Made up story" is not included in the dictionary definition.
Exactly. Science is well within bounds in assuming God created the heavens and the earth and sustains them. Narrow minded ideologues blurt out that this is "unscientific," but they have no evidence to back their claims. Neither do you.
*shrug* I'm telling you what they are, not what people claim they are. Dictionary editors probably worry about boycotts by Christians if they did the same.
No. The accepted definition has nothing to say about the supernatural. It neither includes or excludes it. Only narrow-minded ideologues like yourself are inclined to fabricate a definition of science that suits their fancy.
Dude, if you think that "science" includes the investigation of the supernatural, then you are delusional. (I guess palm readers, ghost hunters, priests and pastors are the same as chemists and physicists. LOL... Witch doctors are just like regular doctors, right... LOL.)
How preposterously small is your expectation when it comes to the capabilities of science! Why not start with something as simple as an automobile, which we know is a product of intelligent design. Are you saying it is impossible for science to test a hypothesis about its design?
In almost every case, an automobile is indirect evidence of intelligent design. Are you saying it is impossble for this to be addressed from a scientific standpoint?
Did you have to see humans making an automobile before you inferred it is the product of intelligent design? Did someone have to sit you down and say, "Now, Horsey honey, this is an automobile, and it was designed by humans" before you correctly inferred it might not have sprung up by itself in the desert or grown out in some farmer's field? Did you have to have it all laid out in formal logic complete with a hypothesis and a theory to back it up? Were you "unscientific" and "mystical" for assuming it was designed when you never even saw who, or what, designed it?
If you want to fabricate your own meanings for words, then it stands to reason you will operate with a skewed view of reality. The dictionary definition of "miracle" denotes it as "an event," not a fiction. There are numerous examples of events to this day for which science does not have an explanation, starting with the fact you are able to remain anchored to this planet.
Have you defined "design?" I don't see where you have done so, so I can hardly see how you are "ahead."
"Horsey, honey" = "Stringneck, baby"
"Have you defined "design?" I don't see where you have done so, so I can hardly see how you are "ahead."
I can't define design, but I am man enough to admit it. You can't either, but you continue to huff and puff as if you could.
...said the man with the invisible friends...
The dictionary definition of "miracle" denotes it as "an event," not a fiction.
Did you ever notice how dictionaries are more concerned with how words are used then whether those uses are factually correct???
There are numerous examples of events to this day for which science does not have an explanation, starting with the fact you are able to remain anchored to this planet.
LOL... Yeah, good luck with investigating that "Angels Pushing Down" theory of gravitation. Or is it the "God Is Blowing Real Hard From Heaven" theory... LMAO
What is unscientific is to make the claim, say it is proper to assume it to be and leave it there. Which is exactly what you do.
Form testing that would facilitate proving your assumption.
Do that testing and draw conclusions from that testing that support or refute your original position. Rework your original assumption(if need be), form tests, draw conclusion from them.........wet, lather, rinse, repeat.....
You, in essence, state that making a claim coming from feeling is all that is needed to qualify it as scientific. Stopping there is indeed unscientific. Take notice, it just doesn't Fit.
I would offer to you that what you do with this topic is like starting your engine at the Indy 500 and never putting the car in gear to run the race. Then still claiming you ran the Indy 500. Claiming it is proper to assume you ran the race because you started your engine. AND THEN, claim anyone that attempts to see anything other than the 'start your engine' portion is wrong for doing so.
You assumed it through indirect evidence. That makes you a "mystic." Had you never seen an automobile in your life, would you think it sprung up in the desert the first time you saw one?
All of scientific thought and testing is formulated in such a manner as to uncover, and understand, intelligent design. Or do you think the aim of science is to uncover chaos? Intelligent design is both the subject and object of science. It is manifest both inductively and deductively. Those who think science is something else are blowing philosophical smoke.
"You assumed it through indirect evidence. That makes you a "mystic."
I never said that indirect evidence was unscientific, that's your lie. I said *theories* with no physical evidence and no testable claims were unscientific. Physical evidence can be either direct or indirect. Theories though HAVE to be testable.
"Had you never seen an automobile in your life, would you think it sprung up in the desert the first time you saw one?"
If I was raised in a culture that had never seen anything like a car, or better yet, one that had next to no technology, I might have no idea what a car was or how it got there. I wasn't, so my assumption was rational.
"All of scientific thought and testing is formulated in such a manner as to uncover, and understand, intelligent design."
No, it is done to uncover REGULARITY and ORDER, not intelligent design.
It's called inductive reasoning. It happens to be convincing to most reasonable people. Like, where there is design there is quite likely a designer. It is your own emotional, pre-conceived notion that leads you to conclude intelligent design is an unscientific concept.
I'm familiar with inductive reasoning. It isn't physical evidence, though. It's an inference, and an emotional one at that.
Words mean things. You are trying to re-define science the way that creationists try to redefine "theory" to suit their agenda.
Why do you suppose no legitimate scientific organization (that is to say, one that has a purpose other than promoting ID) recognizes ID as science? Some global conspiracy stretching back centuries? I'd really like to know.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.