Bioluminescence – A Closer Look

Bioluminescence is a process performed by organisms to produce and emit light. It is created when luciferin, a light emitting molecule, reacts with oxygen. The process can be expedited when an organism produces luciferase.

Luciferase enzymes produce energy in the form of light (BD Editors, 2018), and the application and utilisation of bioluminescence differs amongst specific organisms due to each requiring alternate purposes of use. For instance, some organisms, such as the anglerfish are only able to emit light from its head whereas others, like fireflies, can glow from their entire body. Such diverse physical traits offer each organism various advantages for survival.

Not all bioluminescent reactions use luciferase. Some organisms use photoproteins as its primary reactant. The photoprotein alternative emits light like luciferin but does not require luciferase. Aequorea Victoria is a type of jellyfish found deep in the sea, which uses a photoprotein called Aequorin during the process of bioluminescence. This jelly glows from the edge of their
bells in the colours of green and blue (M, n.d.). The photoprotein, Aequorin, has a structure made of three calcium binding domains and a chromophoric ligand known as coelenterazine. When Aequorea reacts with luciferin, the protein is catalysed into a state of coelenteramide called boa corrin. When the coelenteramide is relaxing on the bell, blue light protons are emitted. The energy from Aequorin is taken by the Green-fluorescent protein and re-emitted as green light (Samson, 2010). Specific reasoning behind why these creatures’ glow has not yet been discovered, but scientists hypothesise that the bioluminescent light helps them ward off predators.

Bioluminescence has been adopted by some organisms as a means of defence, in some cases, confusing potential predators. Others use it to search for prey and some, to attract mates. Occasionally, bioluminescent organisms illuminate when disturbed (National Geographic, 2020).
It is estimated that approximately 50% of Jellyfish are bioluminescent but produce light in different ways. Comb jellies create bright flashes to frighten predators whereas Siphonophores create a chain of light releasing thousands of glowing particles, displayed as an imitator of planktons. This disturbs the predator making it confused (Bioluminescence Questions and Answers, n.d.).

Bioluminescence releases a lot of energy, majority of which gets converted into light, with only a little converted into radiant and heat energy (I.Latz, n.d.). A possible counter argument raised toward
this theory by members of the science forum questions whether the efficiency of bioluminescent light only depends on what happens to it when it is released.

The final efficiency of bioluminescence could be affected if the energy used by molecules to react is considered. An organism that is said to be great at producing bioluminescence could have to use a lot
of energy to constantly produce the light (Hamilton, 2009). The process of Bioluminescence varies in different organisms according to their use and production of it.

References

National Geographic. (2020). Retrieved from National Geographic: https://www.nationalgeographic.org/encyclopedia/bioluminescence/

Bioluminescence Questions and Answers. (n.d.). Retrieved from Latz Lanoratory: https://scripps.ucsd.edu/labs/mlatz/bioluminescence/bioluminescence-questions-and-answers/

BD Editors. (21, January 2018). Bioluminescence. Retrieved from Biology Dictionary : https://biologydictionary.net/bioluminescence/

Hamilton, A. (2009, June 2). Bioluminescent efficiency claims misleading? Retrieved from Daily Chess: https://www.dailychess.com/forum/science/bioluminescent-efficiency-claims-misleading.113649

I.Latz, M. (n.d.). Biological Light in the Ocean Darkness. Retrieved from Latz Laboratory: https://scripps.ucsd.edu/labs/mlatz/bioluminescence/biological-light-in-the-ocean-darkness/

M, S. (n.d.). Crystal Jelly, Aequorea Victoria . Retrieved from Cabrillo Marine Aquarium: https://www.cabrillomarineaquarium.org/exhibits/socal-species-details.asp?id=53

Samson, J. (2010, May 30). Bioluminescence in Aequorea victoria.