Another theory for Fire-spit of Dragons... By Flyingfenix (flyingfenix@yahoo.com or flyingfenix@hotmail.com) Notes #1: I read the explanation some gave on the mechanism of the fire dragons spit when they want to... ahem... get rid of something... like these puny humans... some people attribute it to pure magic (miracle-level science for me...), others simply refuse to explain, but as a biochemist I could not see much sense in it and therefore got on my hands the task of writing a better one... Notes #2: This explanation (specially the end) is quite "technical" in the sense of the names of compounds and processes involved. In truth it would not be possible to understand it completely unless you have some background in the field of chemistry/biochemistry and maybe in biology and physics, but I believe the full explanation could give a solid theory (like Star Trek, where all that is lacking is the real machines...) Feel free to email me if you have any questions about it. Feel free to correct my english as well... Hydrocarbon Spit This is the first theory I will try to explain. It is based on the assumption the fire that is spitted (or breathed) is based on light hydrocarbons, ranging from methane (natural gas, 1 carbon atom) to octane (common car fuel, 8 carbon atoms), or some of its derivatives (see below). Therefore, this kind of fire requires the presence of oxigen in the ambient the fire is spitted on. Or the dragon must also produce and breath the oxidant agent mixed with the fuel and ignite it to produce the fire. This way, the fire is merely a variation of our well-known flamethrowers, but until now we were unable to study with more details and conclude if this second mechanism involving oxidizer exists in the wild, though theoretically possible. Which hydrocarbon? How is it produced? How it is breathed? If dragons spit some compound, which one they do? Do they breathe gases of liquids? It is assumed here that dragons probably breathe a mixture of hydrocarbons of 3 to 8 carbon atoms in lenght, some of which may be linear and others branched, saturated and insaturated. (ask a dragon for a sample and do the analysis yourself..., doesn't matter a lot at all!) . These are the easiest compounds the dragon can produce in its normal biochemical reactions, are easy to store (unlike the hydrogen gas of the previous theory and methane or ethane), are quite inert chemically until mixed with an oxidizer (like air) and ignited and because they do not require very complex, pressure resistant structures for its production, storage and elimination. And they have very high calorific power (this is one of the reasons our cars run on gasoline) in contrast with common alcohol, a great property for something that was designed by evolution to burn with the greatest efficiency. Now, over on the biochemical part of the process (at the end of this article), on the anatomy of the fire- gland and the ways of release of the flame. Most dragons release fire through the nose or through the mouth (maybe some of them through both ways), this varies from species to species, and is not very clear which evolutionary facts led to one or another way. In most cases the so-called fire-gland is a system of two small sacks, egg shaped of about 15 to 25 centimeters long (this size refers to a adult small, (five meters) dragon and varies wildly from dragon to dragon), filled with a very volatile and flamable liquid of strong smell. The gland itself is a muscular structure linked to the nervous system, allowing them to control when the fire is spitted. There are two conducts that lead from the gland to the mouth or nose, depending of the dragon species. Since the structure of these ducts are quite similar to the esophagus (though far smaller), they have been misplaced as being some part (or kind) of the esophagus for a long time, as well as the glands were mistaken as a part of the digestive system. The ducts end in a muscular "mouth" that usually folds over itself, both to close the duct and to extinguish any residual fire that may be there when the dragon decides to end the flame. The "Flamethrowing Action" The sequences of actions the dragon does to produce a flame was elucidated through the hard work of our team of seasoned scientists (some of which died in the attempt) and the great help of a dragon friend (no names, please!). Fire-spitting proceeds as follows: - Dragon inhales air deeply (as deep as it wishes to make the flame last longer or shorter, or if the flame itself is to be long or short) and the fire-gland is contracted, forcing the fuel through the ducts and the ducts mouth. - Dragon starts to expel the air and the air flow from the lungs mixes with the fuel forming a fine mist (somewhat like a car's carburator). Simultaneously, the duct-mouth starts a very small amount of a very high heat-releasing reaction (which is being studied right now...), igniting the mist and starting the fire. High-speed photografies shown that these are very finely synchronyzed events and in almost every case the fire starts at the edge of the dragon's mouth. So, it is correct to say that a dragon breathes fire and not spit fire. - Dragon continues to exhale the air, spreading the flame as it wishes. From this we deducted the duration of the flame depends mostly of the amount of air inhaled and the strenght it is blown out of the mouth and shown less relationship with the size of the fire-gland, although the number of fire-spits it can spit is directly regulated by its size (a normal small dragon could spit from three to six times, and recovers at variable rates depending on the individual). However, statistics shown that the age of the dragon (and therefore its experience and training) relates with its ability of producing more efficient flames, longer or shorter, or special effects like the fireball (below). - Finally, when the air ends or the dragon decides to end the flame, first the duct-mouth folds in itself, cutting the flow of fuel, the fire-gland is relaxed and a split second after, the flame ends itself. Again, this is a highly coordinated action taking less than 0.2 seconds. Special Effects Some dragons shown the ability of spitting something more than a simple flame. Some are capable of hurling fireballs of different sizes at their targets, while others are able to control with great precision the lenght, shape, duration and efficiency of the flame. It seems to be involved with the degree of experience the dragon has, which relates directly (but not always) to its age. As well as with humans, there are very strong reasons to believe there are "naturals" in the dragon society, and this ability varies from dragon to dragon. Fireballs: Fireballs are simple "balls" of fire hurled through the fire or nose of dragon. They seem to be created (and this is being studied) by conscient compression of the fuel-air mist created in the mouth or nose of the dragon followed by its sudden (but controlled) release in the air. Nothing was concluded about the presence of a core of fuel in the ball. At least until now. Fine Control of Flame: This seems to be achieved through training (or natural ability). This allows to control the flow of fuel, air, its mixing, speed and so on, but, again, we are conducting aerodinamic computer- simulations to best understand this control. Another Effects Other kinds (or species) of dragons may produce effects very different from simple fire. Some are able to spit acids (through ways somewhat analogous to the fire-spitting), poisons and so on. These effects may be explained with simple knowledge of the biochemistry, anatomy and physiology of the dragons, but there are others, like the lightning breathers or the frost breathers. Unfortunately, our preliminary studies have shown nothing conclusive, and most believe the answers are in the field of the miracle-level science (mostly known as magic), which some creatures master with ease and humans have not been able to understand it scientifically so far. The quest therefore is far from the end. Final Notes Nothing stated here is said to be definitive, since our knowledge about the vast world of mythical creatures is very small and we cannot underestimate things in a field where humans may be compared to a child. We hope you enjoy this information since we had to do great efforts to make it available. This branch of science is very new and sudden, radical changes are around the corner. The information above is almost not-understandable by people without scientific background. So, if you do not want to be confused by heavy p-science, stop here!!! (Although it makes the theory quite solid and plausible...) The hydrocarbons are produced by the normal methabolism of lipids (fats) in the cells of the dragon, more specifically talking, this reaction in particular occurs in the most extent in the liver, as a part of the lipid assimilation from the food. Well, meat, in special the meat eaten from sedentarious animals (like humans or cattle) may have a lot of fat, but plant food also may have a great amount of fat in the form of oils. Obviously, most of this fat is naturally metabolised in the energy generation processes of the dragon's body, only a minor amout is deviated to the process of fuel production. There is nothing special about the absorption of fats in dragons (except their incredible powerful enzymes capable of digesting the hardest hide ou meat). Usually, the fats apported to the liver are then processed through the beta-oxidation pathway, for the energetic processes, being mostly converted in ATP and exported out of the mitochondrion. However, in dragons, there are a set of mitochondrial membrane proteins plus an enztme for the descarboxilation of uncompletely oxidized chain of the fatty acid. 1) The decarboxilase enzyme: This enzyme is a bifunctional, water-soluble complex formed by two subunits of 85 and 10 kD of molecular weight. Studies done on the kinetics of this enzyme from several subespecies of dragons have shown that kcat is maximum for the small fatty acids, from four to seven carbons long, and is very low for the other lenghts of chain, although is not selective when this chain is branched or substituted. This explained why we were able to detect many derivatives of fatty acids in the fire-gland. The first subunit does the decarboxilation reaction, requiring the fatty acid intermediate, NAD+ and wields NADH, H+, carbon dioxide and the decarboxilated product, which is sequentially bound by the second subunit that acts as a carrier for this molecule to reach the membrane transporter. Since the complex is soluble in the intramitochondrial matrix, this happens through diffusion. This also means the concentration of free decarboxilated products is very low. The low diffusion coefficient of the complex also means the reaction is blocked most of the time, since binding of the hydrocarbon virtually blocks the binding of substrate in the first subunit, and the product is unbound from the carrier only when it reacts with the first membrane transporter. 2) The Mitochondrial Membrane Transporter: This transporter is a 110 kD protein bound and crosssing the outer mitochondrial membrane. It has one binding site for the carbon chain generated by the enzyme complex plus a site which binds one of the chains of the carrier. Binding of the carrier promotes the transfer of a pyrophosphate moiety from the transporter to the carrier, which in turn changes its spatial configuration, releasing the hydrocarbon. Because of the proximity, the newly-released product is bound by the transporter. Hidrolysis of the pyrophosphate releases the carrier from the transporter. The transporter itself only gates to the outside when another molecule of ATP binds the pyrophosphate site, wielding AMP. The hydrocarbon released from the mitochondrion is readily captured by another carrier protein in the cytosol, involved also in the mechanism of vesiculation and exocitosis. Vesicles formed in the liver cells also contain a membrane-bound lipoprotein that is recognized by the fire-gland cells and intermediate its assimilation and storage of the product. Also is included a protein that reduces greatly the solubility of the membranes in the hydrocarbons. In an unusual system, the vesicles pass intact through the fire-gland cells, being digested by protheolythic enzimes in the lumen of the gland and releasing the hydrocarbons. The ignition reaction is being studied now, but seems to be based on the exothermic reaction of an organic peroxide (which releases pure oxigen) and some kind of phosphor containg, unstable compound (probably some derivative of ATP). The reaction seems to produce a very small "spark" of incandescent material that ignites the fuel-air mix. Notes #3: All of the content below is p-science (not to say pseudo-science), and, even if it seems or looks like something real it is not real (It would be wonderful if all the dreams in my heart became real). Not real, Not real and Not real. I hope this was enough for telling you that nothing here is real at all. Hehe. (sigh!) :( Final Disclaimer! I (Flyingfenix, or simply Fenix) wrote all of this and I wish it be spread over the WWW. But only if proper credits are given. And a simple e-mail is sent to me. And no part is cut. Any offense or other harm I may have done or may be doing through the words in this text is not intentional. Tell me if this happen, I will try to correct it if this does not conflict with my beliefs. All rights belong to me. Hehe... :) All english spelling that may be offensive, agressive, funny or simply ridiculous is merely... accidents. And are NOT intentional. And I would be very pleased if someone corrected them for me since my English is FAR than good. All I wanted was to add a little page on the large book of dragon-lore, this time, in a little bit different way (through the scientific point of view). Blame me. Flame me. (Try) to kill me. Hehehe! Do whatever you want! (Let your wings take your dreams high!)