From The Deep Sea to the Crime Lab

Luminescence

Light

•Electrons are energized and photons are released to make light

•The electrons in higher orbitals emit a photon when they fall back to their original orbital

•Our eyes pick up the photons being emitted by the light source

•Chemoluminescence - light produced by a chemical reaction

•Bioluminescence - light produced by a living organism

•Fluorescence - when light is absorbed and re-emitted at a different wavelength

•Phosphorescence - when energy is absorbed and re-emitted but over along period of time

✴These are all examples of COLD light

Luminescence

Bioluminescence

•Used in 90% of deep sea organisms and a few terrestrial organisms

•Used to find prey, hide, and communicate

•Mostly blue and green but some red light as well -- Why?

Uses for Bioluminescence

Counterillumination Use of red light to see prey

Lure preyStun or confuse predators or prey

Attract a mateCommunication

How does it work?

Enzyme

Luciferins

So...

We have seen how organisms can use

luminescence...

How can we use luminescence?

Luminol• Used by crime scene

investigators to detect blood

• The iron in blood acts like a catalyst to activate luminol, producing light

• Helpful in finding blood that may have been cleaned up because traces are left behind

• Bleach will react with luminol, showing if cleaning product has been used

Green Fluorescent Protein

• Aequorea victoria

• Aequorin is the protein, which emits blue light when bound with calcium

• GFP absorbs the blue light and makes it green under UV light

• Osamu Shimomura, Marty Chalfie and Roger Tsien received the Nobel Prize in Chemistry in 2008 for their work with GFP

• Used so we can see where proteins are made and where they end up

• helpful in cancer, Alzheimer’s, and HIV research

Brainbow