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)
What does indirect evidence have to do with it?
The reason ID is not considered science is because of the difficulties inherent in knowing the design status of an object when nothing is known about the designer. It does no good to have as many false positives as correct results. Get the people at DI to fix the problems with ID then talk about getting it into science.
Genesis 27. the LORD God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.
8. Now the LORD God had planted a garden in the east, in Eden; and there he put the man he had formed.
9. And the LORD God made all kinds of trees grow out of the ground--trees that were pleasing to the eye and good for food. In the middle of the garden were the tree of life and the tree of the knowledge of good and evil.
10. A river watering the garden flowed from Eden; from there it was separated into four headwaters.
11. The name of the first is the Pishon; it winds through the entire land of Havilah, where there is gold.
12. (The gold of that land is good; aromatic resin and onyx are also there.)
13. The name of the second river is the Gihon; it winds through the entire land of Cush.
14. The name of the third river is the Tigris; it runs along the east side of Asshur. And the fourth river is the Euphrates.
15. The LORD God took the man and put him in the Garden of Eden to work it and take care of it.
16. And the LORD God commanded the man, "You are free to eat from any tree in the garden;
17. but you must not eat from the tree of the knowledge of good and evil, for when you eat of it you will surely die."
God did not use a 'threat of punishment' on Adam: HE merely told him what would happen if he did eat of that tree.
You must be a Calvinist.
(No... that NOT who the Calvinasaurus is named after!)
No. Just a man.
In thermodynamics, spontaneous means that any energy available in an object for diffusing will spread out if given a chance.
The applied energy and its result are indeed quantifiable mathematically, but it has nothing to do with design. Its a part of the natural interactions between atoms. Being quantifiable mathematically does not imply design.
Indirect evidence has a great deal to do with science, and vise versa. The evidence for intelligent design is largely indirect. The only inherent difficulties in ascertaining whether an object is designed or not occur when there is no physical matter to observe or quantify, IOW total chaos. Put another way, if all the universe were a black hole, intelligent design would perhaps be sorely lacking in physical evidence.
Not when compared to the 'homid' pictures. THEY don't hop around!
But... I'm halfway there now!
I ain't typical.
There is no PROOF that any of those heads led to or came from the other ones!
The evidence for intelligent design is largely indirect imaginary.
Fixed it for you.
Yet it does not stretch credulity to think that a Supreme Being just exists? A Supreme Being who possesses the complexity to design/create wonderous things like DNA and RNA?
One of the basic questions of childhood is, "Where did God come from?" I have yet to come across an explanation that does not also fit the natural universe.
So if it's just natural interaction between atoms, and there is no apparent design, then it is a matter that attains to the level of "scientific." And it would be an "unscientific" notion to posit that perhaps what appears to be "random" or "unguided" may actually be designed and executed according to established rules, laws, etc. I see.
You are correct, my apologies.
However this does not change my point. For the existence of 'information' to provide evidence for a designer it is necessary to have evidence that information can only be produced by a designer.
Do you drive your imaginary car to work, or carry your lunch?
Many people working in science and engineering disciplines have faith. Their faith, even their disparate faiths in Judaism, Christianity, Hindusism, etc, does not prevent them from understanding what science is and how it works and working together on it.
However, attempting to shoehorn theology into biology and chemistry, as you are trying to do, does a disservice to both faith and science. I personally believe that the God-of-the-Gaps not only makes for bad science, but bad theology as well.
How can information be produced and delivered without any aspect of design or intelligence? Is it "unscientific" to suggest design and intelligence are often part and parcel of producing information and then executing functions based upon that information?
As an aside, this is why people lose patience with these threads. How many times must people explain the same, basic concepts?
Minor nitpick: the motto "Gott mit uns" was on the belt buckle of the Wehrmacht which inherited it from the Reichswehr (the Reichswehr IIRC also inherited the motto from pre-WW1 units).
The motto on the SS belt buckle was actually "Meine Ehre heisst Treue".
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