Complementary base pairs: purine-pyrimidinepairs; sugar-phosphate backbone; 2 DNA strands wound around one another to produce a double helix; stabilized in part by hydrogen bonds between nitrogenous bases on either strand; due to the geometry of the bases & amount of space available in helix, H bonds only form when A and T w/ 2 bonds or G and C w/ 3 bonds line up on opposite strands
Using high-resolution atomic force microscopy, a hydrogen bond has been imaged for the first time. This technique is quite similar to the one used to photograph bonds breaking and reforming that was announced earlier this year.
Hydrogen bonding between water molecules. H bonding is responsible for many of the important properties of water such as high cohesion, surface tension, boiling point and its role as a universal solvent.