Page 75 - World of Animals - Issue #28 Magazine

Living light

Who glows there?

From recycling the Sun’s rays to complex chemical reactions, there are various types of glow

Bioluminescence

Creating light from darkness

The term bioluminescence is used to which is why deep-sea creatures like

describe light that is produced by a anglerfish can use it to lure their prey.
chemical reaction inside an organism. There are at least four different types
The vital substance in this reaction is of luciferin in animals, each with
luciferin, which can react with oxygen a corresponding luciferase. Some
to produce light. The process is aided bioluminescent species rely on a
by the enzyme luciferase, but doesn’t supply of these molecules within their
need an external source of light, diet, as they are unable to create them.

Oxygen 1. Luciferin binds
1 2 Photons of light to oxygen, aided
by the enzyme
luciferase.
Luciferase 2. Luciferin reacts
Luciferin with oxygen,
producing
photons, or
light particles.
Fluorescence

Simple light exchange

Unlike bioluminescence, this process reflected, the photons lose energy,

relies on an external light source. meaning the visible glow differs in

The light is absorbed by atoms and colour to the light source. Butterfly
re-emitted again almost immediately. wings contain fluorescent pigments

If the light source disappears, so that intensify their colour, to attract

does the fluorescence. While being mates or repel predators.
Blue light Green light 1. Light is absorbed into the

Electrons fluorescent molecule
1 2 3 4 2. The electrons gain energy and
become excited
3. The electrons return to their
original state, and re-emit the light
Atomic nuclei 4. The emitted light is a different
colour, as it has lost energy
Phosphorescence

The light that lingers

Like a glow-in-the-dark sticker, source, such as the Sun. However, the
phosphorescent animals absorb light electrons become excited to a higher

and use it to give off an eerie glow. degree than in fluorescence and they

The process is similar to fluorescence, release light slowly, at a lower intensity.

but phosphorescent animals can ‘save Animals like jellyfish absorb light at the
up’ light and then release it slowly. Like water’s surface, giving them a glow

fluorescence, this depends on a light that alarms and repels predators.
Electrons 1. Light hits electrons in
phosphorescent molecules
2. This causes the electrons
to enter a high-energy state.
3. The electrons return to
1 2 3 their normal energy state
Atomic nucleus slowly, releasing a soft glow
as they do so.
75