The Chemistry of Bioluminescence

One of nature’s wonders is the ability of living things to produce their own light. This phenomenon is known as bioluminescence, and occurs in several species across the planet. Explore the chemistry behind this phenomenon with an exciting chemical experiment.

This activity was created by Gianluca Farusi and Susan Watt, who created a great experiment to demonstrate this chemical reaction. This experiment demonstrates the kind of chemical reaction that occurs to create bioluminescence.

Grades: 9-12

Background

Bioluminescence is the ability of a living organism to produce light in the form of a chemical reaction. This phenomenon is mostly observed in deep-ocean species such as angler fish, squid, and plankton. There are some terrestrial species such as glow worms that can produce their own light as well. Bioluminescence serves many functions depending on the species.

800px-Shrimp_Bioluminescence_(23503861701)

Some species use bioluminescence as a way to divert and avoid predators. Deep-sea shrimp spit out a glob of bioluminescent goo with a delayed reaction as a means of avoiding and confusing its predators. The infamous angler fish uses bioluminescence to lure in prey, while other deep sea-predators can use their light as infra-red invisible headlights.

The chemical reaction requires a few basic ingredients: oxygen, luciferin, and luciferase. With luciferase as an enzyme, luciferin combines with oxygen to produce energy in the form of light. Different species use different chemical compounds to produce different kinds and colors of light. Fun fact: most deep-sea fish species cannot see the color red, so some predators emit a glowing red light to help them find prey without being detected.

biolum

What You’ll Need

In order to complete this experiment, you’ll need the following items:

  • 1 g luminol (5-amino-2,3-dihydrophthalazine-1,4-dione)
  • 50 ml sodium hydroxide (NaOH) 10% w/w solution
  • 50 ml potassium ferricyanide (K3[Fe(CN)6]) 3% w/w solution
  • Approximately 0.5 g potassium ferricyanide (K3[Fe(CN)6])
  • 3 ml hydrogen peroxide (H2O2) 30% m/m solution
  • Distilled water
  • Beakers
  • Funnel
  • Cylinders
  • Flask

What To Do

These instructions come directly from the authors:

  1. In a beaker, dissolve 1 g luminol in 450 ml distilled water.
  2. Add 50 ml 10% sodium hydroxide solution and mix.
  3. Take 50 ml of the resulting solution and add it to 350 ml distilled water in another beaker. This is now Solution A.
  4. In a third beaker, mix 50 ml 3% potassium ferricyanide solution with 350 ml distilled water and 3 ml 30% hydrogen peroxide solution. This is Solution B.
  5. Pour equal amounts of Solutions A and B into separate cylinders.
  6. Put some potassium ferricyanide into the flask, and place the funnel on the flask.
  7. Move the flask to a dark place.
  8. Pour Solutions A and B into the flask at the same time, and watch what happens.

Safety note from the authors:

Safety glasses, a lab coat and safety gloves should be worn. Care should be taken when handling the 30% hydrogen peroxide solution, as this can react violently in the presence of a catalyst. Close the bottle as soon as you have removed your 3 ml of solution.

 

Here’s a great video to show you what you can expect!

 

Connecting Concepts

Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.
Disciplinary Core Ideas:

PS1.A: Structure and Properties of Matter

  • A stable molecule has less energy than the same set of atoms separated; one must provide at least this energy in order to take the molecule apart.

PS1.B: Chemical Reactions

  • Chemical processes, their rates, and whether or not energy is stored or released can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy.
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