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Bioluminscence Greek bios = living Latin lumen = light the production and emission of light by a living organism as the result of a chemical reaction between two different chemicals during which chemical energy is converted to light energy. Most of the world's bioluminescence exists in the ocean. Of the marine animal phyla, 14 have members that produce light, more than half of all animal phyla capable of bioluminescence. Bioluminescent life forms live mostly in the twilight or disphotic zone – the poorly lit part of the ocean. Natural Bioluminescence Cells contain a chemical called luciferin and make an enzyme called luciferase. To make light, the luciferin combines with oxygen to form an inactive molecule called oxyluciferin. The luciferase speeds up the reaction, which occurs in two steps: 1. luciferin + ATP -------------> luciferyl adenylate + PPi 1. luciferyl adenylate + O2 -------------> oxyluciferin +AMP + light The cells that make the light have uric acid crystals that help reflect the light away from the abdomen. The oxygen is supplied to the cells through a tube in the abdomen called the abdominal trachea. It is not known whether the on-off switching of the light is controlled by nerve cells or the oxygen supply. Uses for Bioluminscence Communication: Fireflies flash at one another in a species-specific pattern, often to find a mate. Locating food: In the depths of the ocean, some fish species use their light like a spotlight to find prey. Attracting prey: Some species, like the angler fish, use a luminescent lure to attract other fish. Camouflage: In the darker parts of the ocean, it's hard to see anything below you, but it's easy to see the silhouette of what's above you. For this reason, some species produce spots of light on their undersides, which blur their outlines and allow them to blend in with the light from above. This is also known as counter-illumination. Mimicry: The cookie-cutter shark has one unlit patch on its underside, which resembles a smaller fish when viewed from below. When a large predator approaches, the shark can take a large bite and then flee. This allows the cookie-cutter shark to prey on animals that are much larger and more powerful than itself. Self-defense: When threatened, some animals release a cloud of bioluminescent fluid, similar to the way squid defend themselves with a cloud of ink. Others use a bright flash to blind predators. Found in: Marine Vertebrates Marine Invertebrates Microorganisms Terrestrial Animals Symbiotic organisms within larger organisms hydromedusa Aequorea victoria is probably the most influential bioluminescent marine organism. Remember Transgenic Organisms???!! FLUORESCENCE – as in bulbs There is a stream of electrons flowing between the electrodes at both ends of the fluorescent bulb. The electrons interact with mercury vapour atoms floating inside the bulb. The mercury atoms become excited, and when they return to an unexcited state they release photons of light in the ultraviolet region of the spectrum. These ultraviolet photons collide with the phosphor coating the inside of the bulb, and the phosphor creates visible light. The phosphor fluoresces to produce light. A fluorescent bulb produces less heat, so it is much more efficient. A fluorescent bulb can produce between 50 and 100 lumens per watt. This makes fluorescent bulbs four to six times more efficient than incandescent bulbs. That's why you can buy a 15-watt fluorescent bulb that produces the same amount of light as a 60-watt incandescent bulb. Flourescence There is a chemical in the shell of the scorpion that makes it glow under long wavelength UV light. Baby scorpions do not glow. Phosphorescence Glow in the dark stickers The excited product is more stable, so that the time until the energy is released is much longer, resulting in a glow long after the light has been shut off. Chemiluminesence 1. The hydrogen peroxide oxidizes the phenyl oxalate ester, resulting in a chemical called phenol and an unstable peroxyacid ester. 2. The unstable peroxyacid ester decomposes, resulting in additional phenol and a cyclic peroxy compound. 3. The cyclic peroxy compound decomposes to carbon dioxide. 4. This decomposition releases energy to the dye. 5. The electrons in the dye atoms jump to a higher level, then fall back down, releasing energy in light. the form of light. Triboluminescence Occurs when molecules (crystalline sugars) are crushed, forcing electrons out of their atomic fields. Free electrons bump into nitrogen molecules in the air. When they collide, the electrons impart energy to the nitrogen molecules, causing them to vibrate. In this excited state, and in order to get rid of the excess energy, these nitrogen molecules emit light. Triboluminescence Are You Ready For Some Fun?! methyl salicylate How it works… 1. When you shatter the sugar crystals with your teeth, electrons (which are negatively charged) break free. As a result, the atoms in which the electrons were formerly embedded become positively charged. 2. As the sugar crystals disintegrate, nitrogen molecules from the air attach themselves to the fractured surfaces. When the free electrons strike the nitrogen molecules, they cause the latter to emit invisible ultraviolet radiation, along with a faint visible glow. 3. The UV radiation is absorbed by the wintergreen flavoring, methyl salicylate, which is fluorescent. This then emits the fairly bright blue light you see.
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