Bio luminescence is the production and emission of light by a living organism. It occurs widely in marine vertebrates and invertebrates, as well as bacteria, fungi and terrestrial animals.
The mechanism of bio luminescence involves a chemical reaction in which light is produced from an excited state intermediate. The primary energy source for this process is generally ATP, although some species can utilize other molecules such as NADH or GTP. In general, the excited state intermediate is generated via oxidation of a luciferin substrate; however, some enzymes are capable of directly converting ATP to light without an intervening substrate (e.g., bacterial luciferases).
The major advantage of bio luminescence over other methods of producing light is that it does not require oxygen to generate the excited state intermediate. This allows for the possibility of using bio luminescence in environments where oxygen is not present or where it would be undesirable to use oxygen-based lighting (e.g., underwater). Another advantage is that many organisms can produce their own light, eliminating the need for an external power source.
There are several disadvantages to using bio luminescence as a method of producing light. One major disadvantage is that it is generally much less efficient than other methods such as incandescent lighting; only a small fraction of the energy used to generate ATP is converted into visible light. Additionally, most organisms that produce their own light do so at relatively low intensities; brighter lights generally require more energy and may not be sustainable for long periods of time without an external power source