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Ultra-sensitive microscope reveals DNA processes
New Scientist ^ | November 15, 2005 | Gaia [sic] Vince

Posted on 11/16/2005 3:40:35 AM PST by snarks_when_bored

Ultra-sensitive microscope reveals DNA processes

    * 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)


TOPICS: Culture/Society; Extended News; Miscellaneous
KEYWORDS: biology; chemistry; crevolist; dna; microscopy; rna; rnap; science
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To: GOPPachyderm

You're ducking the question.

An increase in entropy is proportional to the amount of heat transferred at constant temperature. If you're going to make the claim that life is impossible based on this, you should be able to show it using calculations based on this relationship (no one's done this yet as far as I know).

I don't see anything in your post except for the rehashed 19th century interpretations of the second law and some out of context quotations.


401 posted on 11/16/2005 2:19:41 PM PST by <1/1,000,000th%
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To: furball4paws

An old person of Troy
Was so prudish and coy
That ID doesn't know yet
If it's a girl or a boy.

(O. Nash, mangled by ol' fb4p)


402 posted on 11/16/2005 2:20:08 PM PST by furball4paws (One of the last Evil Geniuses, or the first of their return.)
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To: Elsie
WHY do you feel that it would 'drive' someone in the direction you claim?

It might not drive everyone that way, but the more familiar anyone is with the physical evidence that falsifies the kind of highly literal biblical interpretation that you espouse, the more likely your approach is to convince them to reject the bible entirely. You tell them "all or nothing", they can see from the physical evidence that "all" is false, therefore if they follow your logic they must entirely reject the bible.

403 posted on 11/16/2005 2:25:32 PM PST by Thatcherite (F--ked in the afterlife, bullying feminized androgenous automaton euro-weenie blackguard)
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To: furball4paws
A mighty creature is the germ,
Though smaller than the pachyderm,
His strange delight he often pleases,
By giving people strange diseases.

Ogden Nash bump :)

404 posted on 11/16/2005 2:25:59 PM PST by Liberal Classic (No better friend, no worse enemy. Semper Fi.)
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To: r9etb; Dimensio; js1138; Thatcherite
You've made many posts on this thread that are wildly inaccurate generalizations as to who makes ID claims,

Example?

what their motives are,

Example?

what their strategies might be,

Example?

not to mention making scurrilous claims about various tenets of religious belief.

Example?

When challenged, you responded by ignoring the challenge, and merely repeated your claims. <

Where? Post an example.

I do note that we've had a couple of civil exchanges, too. That's much to be desired.

Indeed.

However, your accusatory posts were and remain dishonest.

No, they most certainly are not. They are my honest assessment, based on many years of experience and research on this issue. I may conceivably be mistaken on one or more points, but I am *not* dishonest about it, and I find your accusation deeply offensive, and it is wholly false.

And speaking of dishonest discussion, I note that you have COMPLETELY DODGED the following TWO portions of the post of mine to which you are responding:

Please explain your behavior. Or, alternately, feel free to *document* the times and places I have done the things you have accused me of, and make your case for why you think I've been dishonest (as opposed to, say, misunderstanding a point). When I accuse someone of being dishonest or making a misrepresentation, I point out the passage of theirs which leads me to this conclusion, and I support the reasons for my conclusion.
Is there any "special reason" you felt no need to either explain your false accusations, or actually DOCUMENT them? Restating your accusations doesn't count, son. Instead, it just makes you look suspiciously evasive.

Also, you have YET AGAIN dodged the following question -- is that very honest of you?

[...] as is your the fact that you have FOR THE THIRD TIME dodged answering the question I asked originally which outraged you so much that you went off on an irrelevant rant about genocide. Here it is again -- care to take another stab at it, or would you like to dodge and make false accusations against me some more?

Finally, your desperate attempt to distract from the question by pointing to a few mass murderers just doesn't answer the question -- why is it that it's the *creationists* who lie so frequently and unashamedly on these discussions, and not the allegedly "godless" evolutionists? Please explain.
Dodge *again* (and have me call you on it again), or just answer the question for a change. Your choice.
So here we go around the mulberry bush again -- I'm calling you on your evasion AGAIN, just as I promised I would if you dodged it again. This is the FOURTH TIME you've dodged actually answering the question. Care to make it five?

Or would you like to actually address it finally, *and* actually document these "lies" you keep saying I have told but keep failing to document? Or, feel free to just retract your slander if you realize you can't document it after all.

405 posted on 11/16/2005 2:26:23 PM PST by Ichneumon
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To: Liberal Classic

You left out:

His customary dwelling place
Is deep within the human race

(or something like that)


406 posted on 11/16/2005 2:27:20 PM PST by furball4paws (One of the last Evil Geniuses, or the first of their return.)
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To: Fester Chugabrew
That's a cop out, too. Science doesn't do that. Science has ways of knowing. Science is not in the business of telling itself what it cannot do, or what it cannot explore. Most reasonable people, however, would rule out "the flatulence of a Cosmic Deity" as a source or cause behind organized matter, dontcha think?

D@mn! Just which version of Fester The Ignorant are you? I know you've heard of The Great Green Arkleseizure!

407 posted on 11/16/2005 2:27:31 PM PST by balrog666 (A myth by any other name is still inane.)
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To: furball4paws
You explicitly said that what I do is ID. The "inventor" of ID, Behe, says the designer is God.

Citation, please. I can give you this article, however, which states Behe's claim as follows: "Behe said the evidence shows design in living organisms, but 'ID leaves the identity of the designer open.'"

Nevertheless, regardless of what Behe may or may not have said, the facts that you actually perform ID, and that you are not God, demonstrate that it is not necessary to impose a supernatural component onto the hypothesis.

Therefore either I am God and order you back under the rug you crawled out from or you are being coy.

Or none of the above, and you are wrong.

408 posted on 11/16/2005 2:29:18 PM PST by r9etb
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To: furball4paws
Oh, my mistake!

Here's the whole thing:

A mighty creature is the germ,
Though smaller than the pachyderm.
His customary dwelling place
Is deep within the human race.
His childish pride he often pleases
By giving people strange diseases.
Do you, my poppet, feel infirm?
You probably contain a germ.

409 posted on 11/16/2005 2:29:26 PM PST by Liberal Classic (No better friend, no worse enemy. Semper Fi.)
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To: balrog666

Just wait and a new one will enter the building.


410 posted on 11/16/2005 2:29:52 PM PST by furball4paws (One of the last Evil Geniuses, or the first of their return.)
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To: Doctor Stochastic
That isn't quite true. ID literature changes its statements depending on the targeted audience.

Dembski: "Indeed, intelligent design is just the Logos theology of John’s Gospel restated in the idiom of information theory."

Indeed, I should have been clear that I was only talking about the version of ID that pretends to try to get itself taken seriously amongst scientists.

411 posted on 11/16/2005 2:30:30 PM PST by Thatcherite (F--ked in the afterlife, bullying feminized androgenous automaton euro-weenie blackguard)
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To: Liberal Classic

I've always felt, well, uneasy about "poppet", but I think finally got the whole thing.

Ogden was always fun and totally harmless.

Candy is dandy
But liquor is quicker.


412 posted on 11/16/2005 2:31:44 PM PST by furball4paws (One of the last Evil Geniuses, or the first of their return.)
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To: r9etb; Dimensio
He can butt out of our personal dispute, thank you very much.

Why?

And it's hardly a "personal dispute" -- you made a broadside against a wide group of people in post #52, and I took you to task for it. As one of the people you were most likely aiming your insult at, Dimensio has as much right to weigh in on it as anyone.

The only reason it resembles a "personal dispute" is because you keep trying to insult me personally (without support or example) as a substitute for actually discussing the SUBJECT I keep trying to bring you back to, and which you have dodged FOUR times now (and counting) returning to your false accusations against me.

If you thought anyone was falling for your diversion, you're mistaken.

413 posted on 11/16/2005 2:32:48 PM PST by Ichneumon
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To: furball4paws
From memory, so possibly slightly innaccurate:

The turtle lives tween plated decks
Which practically conceal its sex
It puzzles me how the turtle
In such a fix can be so furtle

414 posted on 11/16/2005 2:33:46 PM PST by Thatcherite (F--ked in the afterlife, bullying feminized androgenous automaton euro-weenie blackguard)
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To: r9etb

Behe said under oath at the dover trial that he thinks the designer is God.

His words.


415 posted on 11/16/2005 2:33:49 PM PST by furball4paws (One of the last Evil Geniuses, or the first of their return.)
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To: Ichneumon
Exhibit 1) why is it that it's the *creationists* who lie so frequently and unashamedly on these discussions, and not the allegedly "godless" evolutionists? Please explain.

Response: "the creationists" (especially as a group) are not "frequent liars." You may disagree with their assertions (as indeed do I, many times), but they are not purposely telling lies. Assuming you're among the "godless evolutionists," then your oft-repeated claims about the lies makes you a frequent and unashamed liar.

There's more where this came from, but I think this example alone is enough to demonstrate your lack of honesty in dealing with those with whom you disagree.

416 posted on 11/16/2005 2:34:54 PM PST by r9etb
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To: Thatcherite; furball4paws

I give you now Professor Twist,
A conscientious scientist,
Trustees exclaimed, "He never bungles!"
And sent him off to distant jungles.
Camped on a tropic riverside,
One day he missed his loving bride.
She had, the guide informed him later,
Been eaten by an alligator.
Professor Twist could not but smile.
"You mean," he said, "a crocodile."


417 posted on 11/16/2005 2:35:09 PM PST by Liberal Classic (No better friend, no worse enemy. Semper Fi.)
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To: furball4paws
Behe said under oath at the dover trial that he thinks the designer is God. His words.

No, still your words, until you can provide the exact citation.

Nevertheless, I note you're not addressing the fact that you're an intelligent designer who is not God. Thus we see that it is not necessary to invoke God when making the hypothesis.

418 posted on 11/16/2005 2:36:34 PM PST by r9etb
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To: furball4paws; r9etb
Behe said under oath at the dover trial that he thinks the designer is God. His words.

Incidentally, was that before or after he said under oath that it would be a real good idea to teach high school kids that the designer hasn't intervened for hundreds of millions of years, and may well be dead?

419 posted on 11/16/2005 2:36:48 PM PST by Thatcherite (F--ked in the afterlife, bullying feminized androgenous automaton euro-weenie blackguard)
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To: r9etb

No, I'm going to back him up on this. Behe said, under oath, quote, "the designer is God" unquote.


420 posted on 11/16/2005 2:39:38 PM PST by Liberal Classic (No better friend, no worse enemy. Semper Fi.)
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