Bioluminosence chemical reaction

Bioluminescence | chemical reaction

Bioluminescence is the light produced by a chemical reaction,
within a living organism. It is a type of chemiluminescence
where light energy is released by a chemical reaction.

Bioluminescence requires three ingredients: oxygen, a light-e mitting pigment called a luciferin and an enzyme called luciferase. Luciferin is the compound that actually produces

light. In a chemical reaction luciferin is called the substrate.

The bioluminescent colour is a result of the arrangement ofl uciferin molecules.

Some bioluminescent organisms synthesise luciferin ont heir own, 

for examples, bioluminescent dinoflagellates.

However, some bioluminescent organisms absorb it through other organisms, either as food or in a symbioticr elationship, e.g., midshipman fish obtain luciferin through the "seed shrimp" they consume. Luciferase is an enzyme (a catalyst) that interacts with a substrate to affect the rate of a chemical reaction. The luciferase interacts with oxidised

luciferin and produces a byproduct, called oxyluciterin. This chemical reaction also produces light.

Luciferin + O2 ----^( Luciferase) ----> Oxyluciferin + O2 + (Light)

Most of the bioluminescent reactions involve luciferin and

luciferase but some reactions, involve a chemical known as photoprotein. Photoproteins were first studied in bioluminescent crystal jellies found in the west coast of North America. The

photoprotein in crystal jellies is called "green fluorescent protein" or GFP.

Bioluminescence is usefull for animals in the following ways: 
(i) Some species luminesce to confuse attackers,

 e.g.,many species of squid flash to startle predators, such as fish.

(ii) In many animals of the deep sea, bacterial bioluminescence is used for camouflage by counterillumination, in

which the animals matches the overhead environmental light as seen from below.

(iii) It may be used to lure prey or search for prey, 

e.g.,anglerfish causes bioluminescence to lure prey.

(iv) Adult fireflies, also called lightning bugs, light up to attact
mates.
(v) Organisms can luminesce when they are disturbed,
e.g, changes in the environment, such as drop in salinity,
can force bioluminescent algae to glow.
(Vi) Aposematism is a widely used function of biolumine-
Scence, prOviding a warning that the creature concerned is
unpalatable,
 eg, many firefly larvae glow to repel predators.
(vi) Communication in the form of quorum sensing plays a role
in the regulation of luminescence in many species of bacteria.
Small extracellularly secreted molecules stimulate the bacteria to
turn on genes for light production when cell density, measured
by concentration of the secreted molecules, is high.
(vii) It is used by a variety of animals to mimic other species,
e.g, many species of deep sea fish such as the anglerfish and
dragonfish make use of aggressive mimicry to attract prey.
(ix) While most marine bioluminescence is green to blue,
some deep sea barbeled dragonfishes in the genera Aristos-
tomias, Pachystomias and Malacosteus emit a red glow. This
adaptation allows the fish to see red-pigmented prey, which
are normally invisible in the deep ocean environment where
red light has been filtered out by the water column.