The photochemical properties of the luciferase enzyme found in fireflies differ from those of proteins present in bioluminescent bacteria mainly due to the different substrates and mechanisms involved in the light emission process.In fireflies, the enzyme responsible for bioluminescence is called luciferase. The light emission process in fireflies involves the oxidation of a substrate called luciferin. In the presence of luciferase, luciferin reacts with adenosine triphosphate ATP to form a high-energy intermediate called luciferyl adenylate. This intermediate then reacts with molecular oxygen, leading to the formation of an excited state oxyluciferin. The excited oxyluciferin releases energy in the form of light as it returns to its ground state. The color of the emitted light is typically green or yellow, with a wavelength ranging from 510 to 670 nm.In bioluminescent bacteria, the light-emitting proteins are called bacterial luciferases, which are part of a larger family of enzymes known as the lux family. The substrates involved in bacterial bioluminescence are long-chain aliphatic aldehydes, such as tetradecanal, and a reduced flavin mononucleotide FMNH2 . In the presence of bacterial luciferase, the aldehyde and FMNH2 react with molecular oxygen to form a high-energy intermediate. This intermediate then undergoes a series of reactions, ultimately leading to the formation of an excited state flavin. The excited flavin releases energy in the form of light as it returns to its ground state. The color of the emitted light is typically blue-green, with a wavelength of around 490 nm.In summary, the main differences between the photochemical properties of luciferase in fireflies and bioluminescent bacteria are the substrates involved luciferin in fireflies and aliphatic aldehydes in bacteria and the mechanisms of light emission excited state oxyluciferin in fireflies and excited state flavin in bacteria . These differences result in distinct colors and wavelengths of the emitted light in each organism.