iv. Bioluminescence

It is the property by which living beings emit light. Organisms that show this property include Aequorea Victoria, dinoflagellates, firefly squid, and honey fungus. Luciferase enzyme is the photoprotein that catalyzes the biochemical reaction for the emission of light. Luciferin substrate is oxidized in the presence of this enzyme, which leads to its excitation and release of a photon to go back to a stable state. Some can produce their light with the help of this enzyme and others like squid exhibit bioluminescence by forming a symbiosis with bioluminescent organisms.