Photodegradation is degradation of a molecule caused by the absorption of photons, particularly those wavelengths found in sunlight, such as infrared radiation, visible light and ultraviolet light. However, other forms of electromagnetic radiation can cause photodegradation. Photodegradation includes photodissociation, the breakup of molecules into smaller pieces by photons. It also includes the change of a molecules shape to make it irreversibly altered, such as the denaturing of proteins, and the addition of other atoms or molecules. A common photodegradation reaction is oxidation. This type of photodegradation is used by some drinking water and wastewater facilities to destroy pollutants. A molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... In physics, the photon (from Greek φοτος, meaning light) is a quantum of the electromagnetic field, for instance light. ... The wavelength is the distance between repeating units of a wave pattern. ... Prism splitting light Sunlight in the broad sense is the total spectrum of electromagnetic radiation given off by the Sun. ... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... Electromagnetic radiation can be conceptualized as a self propagating transverse oscillating wave of electric and magnetic fields. ... Photodissociation is the breakup of molecules caused by exposure to photons. ... Cheese In biochemistry, denaturation is a structural change in biomolecules such as nucleic acids and proteins, such that they are no longer in their native state (the shape which allows for optimal biological activity). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The most fundamental reactions in chemistry are the redox processes. ... Drinking water Drinking water is water that is intended to be drunk by humans. ... Wastewater is any water that has been adversely affected in quality by any anthropogenic influence. ...