When we see bioluminescence in the ocean what we’re really looking at is millions of tiny plankton, called dinoflagellates, emitting light. But what makes these organisms glow? The answer, of course, is chemistry!
A process called chemiluminescence is used to refer to all light producing reactions. In this specific chemiluminescent reaction, luciferin is reacting with oxygen and luciferase to create oxyluciferin.
Luciferin is a chemical found in the dinoflagellates derived from chlorophyll, the pigment that makes plants and algae green and photosynthetic. The luciferin needs luciferase, a catalyst, to react with oxygen.This reaction creates high energy oxyluciferin which creates light. The oxluciferin can then be converted back to luciferin, but this is a very slow reaction.
The luceriferase catalyst has some amazing uses in biology. Every gene has a promotor region which can either turn the gene on or off. Luciferin can be placed next to this promotor region, and then whatever physical trait that gene acts in glows, that means the gene is on! This has been used in many studies, including some on prostate cancer.
For more on bioluminescence see Jim Morin’s work.