Bioluminescence Sample Presentation – General Power. Point Formatting Example Biology 210 A
Objectives • Define bioluminescence • Identify the types of organisms that utilize bioluminescence • Determine the different advantages of bioluminescence • Examine the chemical process that occurs • Illustrate modern day applications for bioluminescence
What is Bioluminescence? • Bioluminescence is the production and emission of light from a living organism. • The term bioluminescence originated from the Greek bios meaning “living” and the Latin lumen meaning “light”. • The emission of light is produced by chemical reactions within the organism. These reactions can occur internal and external to the cell. • Bioluminescence is not the same as fluorescence as it is the direct production of light where fluorescence is light absorbed, then re-emitted.
• Insects - ex. fireflies, glow worms, certain Types of Organisms That Utilize Bioluminescence centipedes and millipedes • Fish & other marine vertebrates - ex. anglerfish, hatchetfish, cookie cutter shark, gulper eel • Marine invertebrates – ex. many corals and jellyfish, certain squid and mollusks • Fungi – ex. Jack O’Lantern mushroom, ghost fungus, over 70 other species • Other microorganisms – ex. dinoflagellates, and many other bacteria
Advantages of Bioluminescence • to startle or distract another organism to escape from harm • to lure prey • to camouflage/counter shade • to illuminate for visual purposes * A deep sea shrimp emits a bioluminescent fluid to distract a predator to escape • to warn and intimidate other organisms • to communicate and for mating rituals
Chemiluminescence: The Chemical Process • Bioluminescence produces cool light, meaning nearly all energy produced in the reaction is converted to light without heat. • In light bulbs only 3% light is produced, while the remaining 97% of the energy produced is wasted as heat. • The three main requirements for the chemical reaction to occur are: oxygen, luciferin (a molecular substrate) and luciferase (an enzyme) resulting in light and oxyluciferin O 2 + luciferin + luciferase = oxyluciferin + LIGHT
• Sometimes luciferin and additional catalyzing proteins, along with a co-factor such as oxygen, form a complex called a photoprotein. • This molecule is then triggered by a secondary signal molecule, usually calcium ions to activate the complex.
Photophores: The Light House • Many organisms, mostly marine vertebrates and invertebrates, produce bioluminescence in organs called photophores. • These organisms collect light producing bacteria by allowing a small opening to the organ that is exterior to the organism in which the bacteria can enter. • Photophores can be very complex, similar to an eye, in that they can contain a lens, reflectors, and filters. • These features allow the organism to focus the light, control the intensity, and change the color of the light being emitted.
Lux Operon: Expression in Bacteria • The lux operon consists of the gene that codes for luciferase. • The lux system is an inducible operon. • It is active when the concentration of homoserine lactose is high; when a high concentration of bacteria is present. • The lux operon has the sequence lux. CDAB(F)E. • lux. A and lux. B code for the subunits of the enzyme luciferase. • Lux. CDE code for enzymes that convert fatty acids into aldehydes which are needed for the reaction to proceed. • Lux. I is responsible for the production of the autoinducer protein, homoserine lactose. • When the concentration of homoserine lactose is high, it reacts with the protein produced from the second operon, the regulator, lux. R. • This results in increasing the association of RNA polymerase to the promoter region of the first operon and eventually producing luminescence.
Modern Applications of Bioluminescence • Through gene splicing, non-bioluminescent organisms have been able to express the proteins necessary for bioluminescence. Some organisms include: bacteria, silk, potatoes, orchids, and mice. • The biomedical industry uses bioluminescence as a “highlighter” for monitoring the expression of other genes being studied. It has also been used to study infections, the progression of cancer and reconstitution kinetics using bioluminescent stem cells. • Future uses include bioluminescent plants along streets for illumination, advancements in gene therapy and simply for entertainment.
References Bosveld, J. . (2009, July). Aliens of the Sea. Discover, 30(7), 76. Retrieved May 4, 2010, from Research Library Core. Haddock, S. H. D. , Mc. Dougall, C. M. , & Case, J. F. "The Bioluminescence Web Page", http: //lifesci. ucsb. edu/~biolum/ (created 1997; updated 2010; accessed 05/02/10) Latz, M. “Latz Laboratrory of Scripps Institute of Oceanography” http: //siobiolum. ucsd. edu/biolum_intro. html (created 1995; accessed 05/02/10). Rowe, L. , Dikici, E. , & Daunert, S. (Nov 1, 2009). Engineering bioluminescent proteins: expanding their analytical potential. Analytical Chemistry, 81, 21. p. 8662(7). “San Diego Natural History Museum: Lights Alive” http: //www. sdnhm. org/kids/lightsalive/ (accessed 05/02/10).
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