Engineering

Changing shapes at the push of a button

Programmable materials are true shapeshifters. They can change their characteristics in a controlled and reversible way with the push of a button, independently adapting to fit new conditions. They can be used, for example, ...

Energy & Green Tech

Helping green hydrogen out of the lab

There are many steps between a lab breakthrough and real-world application. And green hydrogen may have just taken the first few steps.

Engineering

New natural hydrogel inks for digital light processing 3D printing

Researchers at Politecnico di Torino, BRIN in Indonesia, the Italian Institute of Technology (IIT) and University of Cagliari have recently introduced new composite hydrogel inks based on natural and environment friendly ...

Engineering

Developing "superwood" for infrastructure

With the development of steel and concrete piles over the years, the use of timber piles in civil infrastructure has steadily declined. While timber piles are a renewable and a low-cost foundation system, they have low stiffness ...

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DNA structure

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.

This text uses material from Wikipedia, licensed under CC BY-SA