Ongoing discussion for students in Chemistry III

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Sunday, October 30, 2011

Bioluminescence in Insects

Regardless of the intent of the organism, bioluminescence produces light in the same manner. When an electron circling the nucleus of an atom receives enough energy, it will shift onto a higher electron shell. As the electron moves back to a lower electron shell, energy is released. This energy comes out in the form of a photon, or a light particle, in order to mate, capture prey, and for other reasons.

In order for light to be released through bioluminescence, energy must first be produced in an organism. This happens through a chemical reaction involving luciferin (a molecule that an enzyme reacts with) and an enzyme known as luciferase. The purpose of luciferase is to allow luciferin to release energy during oxidation. Varying chemicals among different organisms result in different colored light being emitted. Differently from that of incandescence, where energy is released in the form of heat, in bioluminescence, energy is released through light, and a negligible amount is lost through heat. Compared to ocean-dwelling organisms, land-based organisms rarely exhibit bioluminescence. In the case of fireflies, the process of bioluminescence differs from other organisms, in that they incorporate the molecule, adenosine tri-phosphate (ATP), into the chemical reaction.

In the insect provided in the example, it is evident that the energy generated is inefficiently being released through heat. Rather than simply emitting light, as almost all bioluminescent organisms do, this one is wasting much of the energy through heat. In spite of the high temperature of the surface of the organism, a combination of factors prevents it from combusting. The first of which includes the presence of oxygen. Although oxygen plays a role in the chemical reactions during bioluminescence, there may not be enough to cause the insect to burn. Another ingredient is fuel, which comes in the form of a variety of chemicals and substances. In addition, all combustion reactions result in heat (known as exothermic reactions). Although combustion results in heat being released, as well as light, there is a distinction between this reaction and bioluminescence. In the case of this insect, it is likely that it simply hasn’t reached a temperature high enough to begin burning, yet is still hot to the touch.


"What Is Bioluminescence?" WiseGEEK: Clear Answers for Common Questions. Web. 30 Oct. 2011. .

"Bioluminescence Questions and Answers." Scripps Institution of Oceanography, 3 Aug. 2000. Web. 30 Oct. 2011. .

"Fire Triangle KidsZone :: Hampshire Fire & Rescue Service." Welcome ...making Hampshire Safer :: Hampshire Fire & Rescue Service. Web. 30 Oct. 2011. .

Video:

http://www.youtube.com/watch?v=UXl8F-eIoiM

1 comment:

Anonymous said...

I agree with your explanation of why species with bioluminescence do not combust. Mentioning the fact that there is not enough oxygen for a combustion to occur was really insightful!