Glowing of Firefly is due to: (AIIMS Nov 2008)
a. The light emitted by fireflies is unique. Nearly 100 percent of the energy is given off as light; in an electric arc light, only 10 percent of the energy is light and the other 90 percent is given off as heat. The taillight contains two rare chemicals, luciferin and luciferase.
b. Luciferin, a heat resistant substrate, is the source of light; luciferase, an enzyme, is the
c. trigger; and oxygen is the fuel. A body chemical, ATP (adenosine triphosphate), converts to
d. energy and causes the luciferin-luciferase mixture to light up.
e. Small internal injections of ATP in the firefly tail cause flashes of light that can be measured quantitatively. As all living
f. cells contain ATP in a rather constant concentration, injection of the firefly's chemicals
g. quickly detects energy problems in human cells (different reaction between normal and cancerous cells).
h. The firefly technique is used to study heart disease, muscular dystrophy, urology, antibiotic testing, waste water treatment, environmental protection and diagnosis of hypothermia in swine-a condition costing the pork industry $200 to $300 million each year. Special electronic detectors, using firefly chemicals, have been placed in spacecrafts to look for earth-life forms in outer space.
i. When as little as one quadrillionth of a gram of ATP enters the rocket's detector, a flash of cold light is given off and the signal is recorded by scientists on earth. Other detectors warn that milk, food or water may be bacteria contaminated.