News tagged with molecules

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

Biophysics explains how immune cells kill bacteria

(Tokyo, August 16) A new data analysis technique, moving subtrajectory analysis, designed by researchers at Tokyo Institute of Technology, defines the dynamics and kinetics of key molecules in the immune response to an infection. ...

Aug 16, 2017
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Cancer detection with sugar molecules

Galectins are a family of proteins that have become a promising source of cancer research in recent years. A representative thereof is galectin-1. It sits on the surface of all human cells; on tumor cells, however, it occurs ...

Aug 14, 2017
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Clues about immune resolution identified in blood

Stopping a wound from bleeding is essential for human health. Blood coagulation - in which blood goes from liquid to gel and forms a clot - can prevent excessive bleeding and infection. But exactly what molecular events transpire ...

Aug 04, 2017
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How blood vessels slow down and accelerate tumor growth

Cancer cells have an enormous need for oxygen and nutrients. Therefore, growing tumors rely on the simultaneous growth of capillaries, the fine branching blood vessels that form their supply network. The formation of new ...

Jul 18, 2017
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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

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