Related topics: cells · protein · atoms · cancer cells · cancer

Math discovery provides new method to study cell activity, aging

New mathematical tools revealing how quickly cell proteins break down are poised to uncover deeper insights into how we age, according to a recently published paper co-authored by a Mississippi State researcher and his colleagues ...

Seeing the color of entangled photons in molecular systems

Spectroscopy is the study of how matter absorbs and emits light and other radiation. It allows scientists to study the structure of atoms and molecules, including the energy levels of their electrons. Classical optical spectroscopy ...

By listening, scientists learn how a protein folds

By converting their data into sounds, scientists discovered how hydrogen bonds contribute to the lightning-fast gyrations that transform a string of amino acids into a functional, folded protein.

page 1 from 40

Molecule

A molecule is defined as a sufficiently stable, electrically neutral group of at least two atoms in a definite arrangement held together by very strong (covalent) chemical bonds. Molecules are distinguished from polyatomic ions in this strict sense. In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and biomolecules.

In the kinetic theory of gases the term molecule is often used for any gaseous particle regardless of its composition. According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.

A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules.

No typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding. In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without any definable molecule, but also without any of the regularity of repeating units that characterises crystals.

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