Helices

thumb|right|upright=1.33|The structure of the DNA double helix (type [[B-DNA). The atoms in the structure are colour-coded by element and the detailed structures of two base pairs are shown in the bottom right.]] thumb|Simplified diagram

thumb|upright=1.35|(l-r) Tension, compression and torsion coil springs thumb|upright|A machine screw thumb|The right-handed helix for with arrowheads showing direction of increasing

type of secondary structure

compressed DNA loop supercoiled by prokaryotes to fit within a small space

bridge in Singapore

the structure formed by double-stranded molecules of nucleic acids such as DNA.

synthetic nucleic acid (eight nucleobases — four natural, and four synthetic)

A type of antenna

group of compounds

secondary protein structure

InterPro Repeat

protein structure

type of secondary structure

artwork by Kenneth Snelson, version at Hirshhorn Sculpture Garden

Type of protein secondary structure

set of three congruent geometrical helices with the same axis

linear stacking of regular tetrahedra