DNA structure

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DNA structure shows a variety of forms, both double-stranded and single-stranded. The mechanical properties of DNA, which are directly related to its structure, are a significant problem for cells. Every process which binds or reads DNA is able to use or modify the mechanical properties of DNA for purposes of recognition, packaging and modification. The extreme length (a chromosome may contain a 10 cm long DNA strand), relative rigidity and helical structure of DNA has led to the evolution of histones and of enzymes such as topoisomerases and helicases to manage a cell's DNA. The properties of DNA are closely related to its molecular structure and sequence, particularly the weakness of the hydrogen bonds and electronic interactions that hold strands of DNA together compared to the strength of the bonds within each strand.

Experimental techniques which can directly measure the mechanical properties of DNA are relatively new, and high-resolution visualization in solution is often difficult. Nevertheless, scientists have uncovered large amount of data on the mechanical properties of this polymer, and the implications of DNA's mechanical properties on cellular processes is a topic of active current research.

It is important to note the DNA found in many cells can be macroscopic in length - a few centimetres long for each human chromosome. Consequently, cells must compact or "package" DNA to carry it within them. In eukaryotes this is carried by spool-like proteins known as histones, around which DNA winds. It is the further compaction of this DNA-protein complex which produces the well known mitotic eukaryotic chromosomes.

For more information about DNA structure, read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with mechanical properties


Tough yet stiff deer antler is materials scientist's dream

Biology / Plants & Animals

created Nov 27, 2009 | popularity 3.4 / 5 (7) | comments 2

Prized for their impressive antlers, red deer have been caught in the hunters' sights for generations. But a deer's antlers are much more than decorative. They are lethal weapons that stags crash together when duelling. John ...





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New results from a terra-ific decade in orbit

New results from a terra-ific decade in orbit

Space & Earth / Earth Sciences

created Dec 15, 2009 | popularity 5 / 5 (1) | comments 0

December 18, 2009, marks the tenth year since the launch of Terra, one of NASA's "flagship" Earth observing satellites. But the decade is more than just a mechanical milestone. With each additional day and ...


Argonne scientists to control attractive force for nanoelectromechanical systems

Nanotechnology / Nanophysics

created Dec 10, 2009 | popularity 3 / 5 (2) | comments 1

Scientists at the U.S. Department of Energy's Argonne National Laboratory are developing a way to control the Casimir force, a quantum mechanical force, which attracts objects when they are only hundred nanometers apart.


Lightweight composites to get trimmer and smarter

Lightweight composites to get trimmer and smarter

Nanotechnology / Nanomaterials

created Dec 10, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- CSIRO researchers have set themselves the goal of producing a new generation of super-strong, lightweight polymer composite materials for use in aircraft, road vehicles, trains and ferries.


Plate-eating good: University of Montreal professor designs edible tableware

Other Sciences / Other

created Dec 08, 2009 | popularity not rated yet | comments 0

Finishing your plate may soon take on a literal meaning. Diane Bisson, a professor at the Université de Montréal School of Industrial Design, has fashioned edible plates that are practical, stylish and tasty. ...


Super cool atom thermometer

Super cool atom thermometer

Physics / General Physics

created Dec 07, 2009 | popularity 5 / 5 (2) | comments 0

As physicists strive to cool atoms down to ever more frigid temperatures, they face the daunting task of developing new, reliable ways of measuring these extreme lows. Now a team of physicists has devised ...


Physicist Jack Harris Is Honored by DARPA as One of Nation's 'Rising Stars'

Physics / General Physics

created Dec 04, 2009 | popularity 5 / 5 (1) | comments 0

(PhysOrg.com) -- Jack Harris, an associate professor of physics, has received one of this year's Young Faculty Awards (YFA) from the Defense Advanced Research Projects Agency (DARPA). He is one of 33 "rising stars" across ...


Shape shifters: Researchers create new breed of antennas

Shape shifters: Researchers create new breed of antennas

Technology / Engineering

created Dec 01, 2009 | popularity 4.7 / 5 (13) | comments 4

(PhysOrg.com) -- Antennas aren't just for listening to the radio anymore. They're used in everything from cell phones to GPS devices. Research from North Carolina State University is revolutionizing the field ...


Elastography reduces unnecessary breast biopsies

Medicine & Health / Cancer

created Nov 30, 2009 | popularity not rated yet | comments 0

Elastography is an effective, convenient technique that, when added to breast ultrasound, helps distinguish cancerous breast lesions from benign results, according to an ongoing study presented today at the annual meeting ...


Tissue tension regulates tumor progression

Medicine & Health / Cancer

created Nov 23, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- UCSF scientists have shown for the first time that the rigidity of a tissue can induce cancer. The research team identified an enzyme that is crucial for regulating tissue stiffness and demonstrated that ...


Water droplets direct self-assembly process in thin-film materials

Nanotechnology / Nanomaterials

created Nov 23, 2009 | popularity 5 / 5 (5) | comments 2

You can think of it as origami - very high-tech origami. Researchers at the University of Illinois have developed a technique for fabricating three-dimensional, single-crystalline silicon structures from thin films by coupling ...



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