BIOLUMINESCENCE. Submitted by, SELMA ABDUL SAMAD BCH- 10 – 05 – 02 S2 MSc BIOCHEMISTRY. Phenomenon of production and emission of light by a living organism. Creatures ( unicellular bacteria to vertebrates ) chemical energy Light energy ( Wilson and Hastings, 1998)
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SELMA ABDUL SAMAD
BCH- 10 – 05 – 02
S2 MSc BIOCHEMISTRY
chemical energy Light energy
(Wilson and Hastings, 1998)
Are mostly - marine
Very few - terrestrial
The molecule absorbs a photon and excites an electron It comes back to low energy state releasing energy in the form of light.(Williamson & Cummins,1983)
The original molecule is restored following fluorescent emission.
The expended molecule must be replaced by synthesis or diet, it is not regenerated.
(Vargula & Cypridina)
(Wilson & Hastings,1998)
(William & Hastings,1998)
But its physiological implementation is extremely variegated.
b) make primary predator visible to larger
They bioluminesce and produce beautiful displays during red tide blooms.
Where light is still available
~90% of animals in mesopelagic zone (200-1000 m depth)
- Some squids – symbiotic association of biolum.bacteria – uses their bioluminescence to match envir. light
Some animals bioluminesce blue on their underbellies – the color blends with blue color of the surface water – thus masks them from the predators lurking below.
Repulsion of predators – certain squids and shrimps give out biolum. bacterial slurry,like smoke that repels predators.
Eg. Fireflies , centipedes , millipedes , worms
Warning potential predators that they do not taste pleasant
(They also bioluminesce to procure food)
Eg. Isistius brasiliensis (cookie-cutter shark)
Underbelly bioluminesce except a patch of skin near the throat
- appears like a small fish & attracts large predators
- suctions to large fish , clamps with teeth into their flesh and cuts and bites off cookie shaped chunk of flesh
Some predators lure prey by mimicking their signals.
- Has 2 different bioluminescent organs
- one produces blue-green light
- the other (under the eye) produces long IR (red) light
- IR light or red light are invisible to most deep sea animals
(other than malacosteus)
- Thus it can see its prey without alerting them
- By varying their light output
- eg. Fireflies and Deep Sea Angler fish
- Signaling by light help choose a compatible mate
- Intensity or Frequency of signals help discern the health
of the mate. (so stronger evolutionary advantage)
eg. Fireflies – light production maybe a continuous glow, a certain frequency of flashes or a sequence of repeated flashes that can alternate in frequency.
- Bacterial lux operon controls bioluminescence
- In many bioluminescent bacteria, it is turned on only when
the bacteria are in high cell densities
(Quorum sensing – The ability of bacteria to regulate gene
expression in response to cell density )
- eg. Vibrio, Photomicrobium etc.
(mainly found in seawater and in symbiotic association
with fishes like angler fish, flashlight fish,
bobtail squid etc)
Not much terrestrial animals – light is abundant and life is restricted to the surface of earth.(fireflies, glow-worms, some larvae, insects, arachnids, annelids , fungi etc)
Family – Lampyridae
About 2000 species
Found in temperate & tropical environments
Their larvae (glow worms) need wet areas.
Arginine Nitric oxide
Luciferyl adenylate + O2 Oxyluciferin + AMP + Light
(Light ~560 nm and 100% efficient)
When oxyluciferin is of - ketoform -- red / green to red light
- enolate from -- yellow-green light
Green, Yellow or pale-red 510 – 670 nm