2.5 - 1.9 (organism making their own light: bioluminescence)

What kind of organisms can make their own light and what is the process called?

Organisms like certain bacteria, algae, fungi, insects, squid, and fish

Through prices called bioluminescence

What is the process of bioluminescence in comparison to absorption of light by a pigment?

Bioluminescence occurs in reverse

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The absorption by pigment involves

• energy of photon transferred to electron
• electron raised from ground to excited state

What kind of organisms can make their own light and what is the process called?

Organisms like certain bacteria, algae, fungi, insects, squid, and fish

Through prices called bioluminescence

What is the process of bioluminescence in comparison to absorption of light by a pigment?

Bioluminescence occurs in reverse

\
The absorption by pigment involves

• energy of photon transferred to electron
• electron raised from ground to excited state

What is the process of bioluminescence?

Chemical energy in the form of ATP excites an electron in a substrate molecule from the ground state to higher excites state

• when electron returns to ground state energy is released as a photon of light

How efficient is the conversion of chemical energy in ATP into light? Compared to light bulb?

Very efficient; less than 5% of energy in ATP is lost as heat

• compared the to energy of light bulb which loses 95% of it as heat

Why is the high efficiency essential?

Because high heat production would be incompatible with life

What kind of uses do bioluminescencent organisms generate light for?

• attracting mate or prey
• camouflage
• communication

What is an example of an organism creating bioluminescence? What use and what triggers it?

Dinoflagellates use bioluminescence as an alarm mechanism to scare off potential predators and to also make them visible in the water in instances like at night

• triggered by disturbance of water surrounding them

What is quorum sensing?

Type of communication used by marine bacteria through bioluminescence

• Individual bacteria release compounds at low concentrations too little to elicit a response
• bacterial populations grow, the size reaches a threshold: a quorum

What is a quorum? What does it result in/what are the results?

Concentration of compounds is high here to elicit a physiological response in all members of the population

• the response results in the activation of certain genes including those that encode for proteins required for bioluminescence

What is quorum sensing believed to be the basis for now?

For “milky seas”

• this strange phenomenon of light on the surface of the ocean has been reported many times over the past several hundred years by sailors and mentioned in book

What kind are most bioluminescence organisms?

They are marine & abundant below 800m - where there is no sunlight

Where haven’t bioluminescence been reported? Why is this?

Not reported in land plants or higher vertebrates

• we don’t know yet