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)
Thank you for adding your ignorant and incorrect opinion to the discussion.
Here's what you're missing:
1. Creationists try to falsely claim that their position is supported by science, or is scientific, in a dishonest attempt to give it an apparent increased legitimacy, or to try to force it into science classrooms where it doesn't belong.
2. Science deals with ideas that are actually testable. This isn't just an arbitrary criteria. It has two very important consequences: a) concepts that aren't testable can't be determined as true or not, they can merely be emptily asserted. And more to the point: b) concepts that aren't testable are irrelevant to the real world, because if they *did* have a practical effect on the real world, *that* would make them testable.
In short, science, by its nature, deals with things that actually matter to reality. Conversely, things that are non-scientific don't really matter whether they're true or not.
"ID", as it currently stands, is a useless postulate, and whether it's true or not, it still doesn't matter, because it has absolutely no consequences either way. (If it *did* have consequences, *then* it would be testable, *and* thus would be subject to scientific examination.)
What does the 1st Law of Thermodynamics support?
Hate is what they mostly do best. After all, they worship a deity who they think is going to punish those who disagree with them for eternity.
I don't know, you'll have to ask those IDists who insist their philosophy has nothing to do with God.
"Must IDer's be atheists now?"
Heck no. They should just stop prevaricating about the designer.
A bit arrogant and ignorant of you to try to tell me about my profession. But that's typical of ID and Creationists. What do you do for a living? I want to know so I can tell you how to it the way I think it should be done.
Nope. ID, as presented to the school boards, is religiously based.
I asked you the following question in another thread, but you unnaccountably forgot to answer, so here goes again:
What conceivable observation would show ID to be false?
Both. Content addressable memory seems to be the head part - it ain't memorized, but if I've heard or read it before, THEN I can use the search function of the online.
Plus I've got lots of canned responses: just like all that red stuff at the beginning(1 'n' or 2?) of this thread ;^)
Soiled diapers.
This is the kind of condescending remark that gives many Christians a bad name.
Interesting definition. You come up with that all by yourself?
For example, for no rational reason you apparently try to paint anybody who says "ID" as a creationist. That's a strawman, and sadly typical of your non-thinking approach to the discussion. (Which, incidentaly, fits one of Webster's definitions for dogma: "a point of view or tenet put forth as authoritative without adequate grounds.")
Second, you claim without justification that an ID hypothesis is "untestable." Not necessarily -- but it's certainly "not testable" if your biases lead you never to try in the first place, and that's where you're headed.
Third, if science deals with things that matter to reality, then science had better learn to deal with ID -- after all, it's something that happens today, and people make good money doing it. Unless you want to tell us that the biotech industry is "non-scientific."
Yup. Looks like you've got your dogma all dressed up and ready to go.
Shouldn't that be the other way round from your point of view? ie Most Christians don't reject the Bible because they do NOT know what their bible says. That is the conclusion that you force people to draw by adopting your all-or-nothing approach if they've seen and understood the physical evidence.
Well then; what do YOU think the Scriptures posted mean?
Nope. I cribbed them from another Freeper. Very little in that compilation is mine. I'm DC's Archivist, not its Ops Manager.
It is for the proponents of an idea to propose tests for it... so... any chance of you suggesting a test that would have the potential to falsify ID?
This is transparently false -- thanks for revealing that you, yourself, actually don't have enough honor or ethics to address the reality.
Furthermore, if it's allegedly the "godless" who have "no honor" and "no ethics", then why is it almost exclusively the *creationists* who are the habitual liars?
Want some examples? Here you go:
Take for example the way that creationst Kent "Dr. Dino" Hovind declares that radiocarbon dating produced wildly different dates for the skin and bones of the same mammoth specimen, in order to attempt to raise questions about the accuracy of radiocarbon dating.For a very recent example, here's something from this week on http://www.pandasthumb.org/ (my highlighting in red):THIS. IS. A. LIE.
Hovind's *own* citation which he gives in "support" of this his false claim -- which is the scientific paper which is the original report on the specimens in question -- states quite clearly that they were DIFFERENT specimens taken from DIFFERENT locations.
When challenged on this point, Hovind gave specimen ID numbers which he claimed were for the samples in question (which, again, Hovind claimed were from the same individual mammoth), and looking up those IDs in the primary literature shows that not only were they indeed NOT from the same mammoth, one of them WASN'T EVEN FROM A MAMMOTH AT ALL (it was from a rhino). Nonetheless, creationist Hovind has never retracted his false claims about the evidence itself.
Freeper Havoc (a creationist) repeated Hovind's lie here on FreeRepublic.
When I pointed out that even Hovind's own citation contradicts Hovind's version, and showed him documentation of that, Havoc mumbled a reply ("you haven't displayed a falsehood, you just make these assertions") and failed to retract the false claim he had repeated from Hovind.
HAVOC THEN REPOSTED THE SAME FALSE CLAIM SHORTLY THEREAFTER ON ANOTHER THREAD.
Summary of the ability of the two creationists (Hovind and Havoc) to present information they *know* is false, and to *fail* to retract when reminded of their falsehoods, is presented here, along with links to all appropriate documentation.
(Quick aside -- Fester, do you condone this behavior of your fellow creationists? Yes or no? Is lying for the "cause" of creationism acceptable to you?)
This sort of behavior, unfortunately, is *typical* of creationists. Here, want dozens of more examples of their distortions? A few more for the road? Another? Still more, perhaps? How about even more? Ooh, here are some good examples. And there's lots more where that came from, like this and this and this and lots more here and *tons* here and countless more here and yet more here, a goodie... Wait, there's more over here, etc., etc., etc., etc., etc., *ETC.*, etc., etc., etc., . How about 300 more creationist misrepresentations? Not enough, you say? Well then visit Creationist Lies and Blunders. And at least half of these are outright lies, repeatedly used long after their dishonesty has been exposed (the rest are merely creationist stupidity, *still* knowingly used after the errors have been explained, which is yet *another* form of creationist dishonesty).
Furthermore, I catch IDers/creationists lying on a regular basis on almost every "crevo" thread here on FreeRepublic.William Dembski [a darling of the "ID"/creationist movement -- Ich.] finally managed to find the transcript of Shallit’s testimony. Since I’ve been correct on predicting his behavior all the way along so far, I’ve taken another stab at it at Dispatches from the Culture Wars.
Update: Holy cow, I missed this the first time. Yesterday I asked the rhetorical question, would Dembski continue to embarrass himself in this situation regarding Shallit’s testimony? Well, we have our answer. Not only is he continuing to embarrass himself, he’s digging the hole even deeper. He’s now compounding his dishonesty with an attempt to erase the past. He has now deleted all three of his previous posts where he made the false claim that Shallit had been pulled from testifying by the ACLU because his deposition was an “embarrassment” and a “liability” to their case, even after one of those posts got almost 100 comments in reply to it. There’s no word so far on whether he will change his name to Winston Smith.
This really is dishonest behavior, there’s no two ways about it. Clearly, Dembski’s world is one in which he thinks he can rewrite history and no one will notice. I’m dying to hear how his toadies will defend this behavior. It’s not defensible on its own, so they can only attempt to distract attention away from it with a tu quoque argument or pointing fingers at others. So let’s hear what they have to say. Salvador? O’Brien? DonaldM? Let’s hear you defend this dishonest and Orwellian behavior. And tell us again how it’s evolution that undermines ethics and morality while you’re at it.
Update #2: Oh, here’s Dembski’s latest on the subject, in a comment responding to being asked what happened to the previous posts on the subject:
The previous postings were a bit of street theater. I now have what I needed. As for responding to Shallit and his criticisms, I have been and continue to do so through a series of technical articles under the rubric “The Mathematical Foundations of Intelligent Design” — you can find these articles at www.designinference.com. The most important of these is titled “Searching Large Spaces.” Shallit has indicated to me that he does not intend to engage that body of work: http://www.uncommondescent.com/index.php/archive….
A bit of street theater? Okay, let me see if I understand this. Dembski engaged in a bit of “street theater” - meaning “told a lie” - to get a copy of the transcript that he could have gotten two months ago because it’s been publicly available all along? And now instead of admitting to the lie, he’s just erasing the evidence of it? Okay, let’s call a spade a spade here. Dembski is a lying scumbag with no regard for the truth whatsoever. Period. Just when you think he’s hit rock bottom, Dembski begins to tunnel.
So tell us again how it's allegedly the "godless" who have no ethics or honor?
Sounds like my wife. People like you and her drive me crazy; I have trouble recovering from memory what I read 20 minutes ago. I know something is in there, but I have no idea where.
"Plus I've got lots of canned responses: just like all that red stuff at the beginning(1 'n' or 2?) of this thread ;^)
(2)
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