THE LIGHT OF FIREFLY

Example of Explanation Text

General Statement

Firefly is a kind of insect which gleams at night. It has a beautiful twinkling flash which makes people are interested to see and do research about its light. As an electric bulb, it also produces the light inside of its body with chemical reaction. However, it is different because the firefly does not produce the energy which contains a lot of heat. The flash is cold. It is because the light producing organ in its body releasing around 100% of energy in the form of light. Thus, it can survive the experience.

Explanation

Fireflies’ light is generated by a special organ that is composed of light-producing cells called Photocyte¹⁾. The organ is situated on the fourth or fifth vertebra of their bodies. The light is on when oxygen combines with calcium Adenisine Triphosphate²⁾ (ATP) and the chemical luciferin³⁾ in the presence of luciferace⁴⁾ or a bioluminescent enzyme.

Explanation

Fireflies do not emit the illumination constantly. They turn the light on and off. It means that there are certain mechanisms in their bodies that play the role like a switch of an electric light that turn on and off the light. The molecule that acts as a switch is a chemical which is called Nitric Oxide (NO) ⁵⁾. The presence of this chemical which binds to the mitochondria⁶⁾ allows oxygen to flow into the light organ where it combines with the other chemicals needed to produce the bioluminescent reaction. Then, the oxygen molecules are trapped by the mitochondria. It is because the nitric oxide breaks down very quickly. Consequently, the oxygen molecules are not anymore available for the production of light.

1)  Cells that are within abdomen of fireflies
2)  Molecule that stores and transport energy in living organisms
3)  Chemical substance produces a light
4)  Enzyme that catalyzes the reaction
5)  A molecule which is produced by cell walls of blood vessels
6)  Organ cells that provide energy