Transcript Bioluminescence

Bioluminscence
Greek bios = living
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Latin lumen = light
the production and emission of light by a living
organism as the result of a chemical reaction between
two different chemicals during which chemical energy is
converted to light energy.
Most of the world's bioluminescence exists in the
ocean. Of the marine animal phyla, 14 have members
that produce light, more than half of all animal phyla
capable of bioluminescence.
Bioluminescent life forms live mostly in the twilight or
disphotic zone – the poorly lit part of the ocean.
Natural Bioluminescence
Cells contain a chemical called luciferin and make an
enzyme called luciferase.
To make light, the luciferin combines with oxygen to form
an inactive molecule called oxyluciferin.
The luciferase speeds up the reaction, which occurs in two
steps:
1. luciferin + ATP -------------> luciferyl adenylate + PPi
1. luciferyl adenylate + O2 -------------> oxyluciferin +AMP +
light
The cells that make the light have uric acid crystals that help reflect the light
away from the abdomen. The oxygen is supplied to the cells through a tube in
the abdomen called the abdominal trachea. It is not known whether the on-off
switching of the light is controlled by nerve cells or the oxygen supply.
Uses for Bioluminscence
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Communication: Fireflies flash at one another in a species-specific pattern, often to
find a mate.
Locating food: In the depths of the ocean, some fish species use their light like a
spotlight to find prey.
Attracting prey: Some species, like the angler fish, use a luminescent lure to attract
other fish.
Camouflage: In the darker parts of the ocean, it's hard to see anything below you, but
it's easy to see the silhouette of what's above you. For this reason, some species
produce spots of light on their undersides, which blur their outlines and allow them to
blend in with the light from above. This is also known as counter-illumination.
Mimicry: The cookie-cutter shark has one unlit patch on its underside, which
resembles a smaller fish when viewed from below. When a large predator approaches,
the shark can take a large bite and then flee. This allows the cookie-cutter shark to prey
on animals that are much larger and more powerful than itself.
Self-defense: When threatened, some animals release a cloud of bioluminescent fluid,
similar to the way squid defend themselves with a cloud of ink. Others use a bright
flash to blind predators.
Found in:
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Marine Vertebrates
Marine Invertebrates
Microorganisms
Terrestrial Animals
Symbiotic organisms within larger
organisms
hydromedusa Aequorea victoria is probably the most
influential bioluminescent marine organism.
Remember Transgenic
Organisms???!!
FLUORESCENCE – as in bulbs
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There is a stream of electrons flowing between the electrodes at both
ends of the fluorescent bulb.
The electrons interact with mercury vapour atoms floating inside the
bulb.
The mercury atoms become excited, and when they return to an
unexcited state they release photons of light in the ultraviolet region of
the spectrum.
These ultraviolet photons collide with the phosphor coating the inside of
the bulb, and the phosphor creates visible light.
The phosphor fluoresces to produce light. A fluorescent bulb produces
less heat, so it is much more efficient. A fluorescent bulb can produce
between 50 and 100 lumens per watt. This makes fluorescent bulbs
four to six times more efficient than incandescent bulbs. That's why
you can buy a 15-watt fluorescent bulb that produces the same amount
of light as a 60-watt incandescent bulb.
Flourescence
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There is a chemical in
the shell of the scorpion
that makes it glow under
long wavelength UV
light.
Baby scorpions do not
glow.
Phosphorescence
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Glow in the dark stickers
The excited product is more
stable, so that the time until
the energy is released is much
longer, resulting in a glow long
after the light has been shut
off.
Chemiluminesence
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The hydrogen peroxide oxidizes
the phenyl oxalate ester, resulting
in a chemical called phenol and an
unstable peroxyacid ester.
The unstable peroxyacid ester
decomposes, resulting in
additional phenol and a cyclic
peroxy compound.
The cyclic peroxy compound
decomposes to carbon dioxide.
This decomposition releases
energy to the dye.
The electrons in the dye atoms
jump to a higher level, then fall
back down, releasing energy in
the form of light.
light.
Triboluminescence
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Occurs when molecules (crystalline sugars) are crushed,
forcing electrons out of their atomic fields. Free
electrons bump into nitrogen molecules in the air.
When they collide, the electrons impart energy to the
nitrogen molecules, causing them to vibrate. In this
excited state, and in order to get rid of the excess
energy, these nitrogen molecules emit light.
Triboluminescence
Are You Ready
For Some
Fun?!
methyl salicylate
How it works…
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When you shatter the sugar crystals with your teeth,
electrons (which are negatively charged) break free. As a
result, the atoms in which the electrons were formerly
embedded become positively charged.
As the sugar crystals disintegrate, nitrogen molecules from
the air attach themselves to the fractured surfaces. When
the free electrons strike the nitrogen molecules, they cause
the latter to emit invisible ultraviolet radiation, along with a
faint visible glow.
The UV radiation is absorbed by the wintergreen flavoring,
methyl salicylate, which is fluorescent. This then emits the
fairly bright blue light you see.