Latest Issue of Science News


Science Visualized

A new twist on a twist

TWISTED  Nature's famous helix formation, which forms the shape of DNA, ram's horns and seashells, can be tuned to make hemihelices — reverse windings of the original structure. Perversions are the changes in direction in a hemihelix.

Nature abounds with perfect helices. They show up in animal horns and seashells, in DNA and the young tendrils of plants. But helix formation can get complicated: In some cases, the direction of rotation can reverse as a helix grows. The resulting structure has been dubbed the hemihelix, and you may have made one yourself by untwisting part of a telephone cord so much that it flips and spirals in the other direction.

This article is available only to subscribing members. Join SSP today or Log in.

More from this issue of Science News