I got a text this week for a #ScienceSunday topic that I just couldn’t say no to! We are going to talk about fireflies/lightning bugs!!! They are a summer night staple making everything glow! Let’s dive in and find out how and why they light up the night sky!!
The whole concept to understand is bioluminescence! It’s a big complicated word that basically means a chemical reaction that lights up something’s body. This reaction occurs when oxygen combines with calcium, adenosine triphosphate (atp) [a form of exerted energy], and luciferin. When these combine, they work with a bioluminescent enzyme luciferase to produce the light we see.
I want to make sure we all understand what each of these molecules does. Oxygen obviously comes from the air the fireflies fly in. Calcium is in their bodies. Adenosine triphosphate is a key component of energy required for reactions like muscle contractions. And luciferin is the compound that produces the light seen from bioluminescence. It only works when the enzyme luciferase is present.
What is really cool about this whole reaction is the idea that the “light” organ at the end of the fireflies body stays cold the entire time. This is because if their bodies got too warm they could die from the heat.
The oxygen is the most important component of the reaction. The more oxygen present the longer the light stays on. When the oxygen is depleted the light goes out. Researchers believe a gas called nitric oxide binds to an organ called mitochondria in the light organ where it is released when oxygen comes through the fireflies body. So the combination of nitric oxide and oxygen allows for the firefly to start and stop the lighting up at any rate they choose which is cool because they can control the speed of their bums lighting up!
Now why does bioluminescence even exist? Well most importantly, as a protection against predators. When a firefly is eaten by a predator, the taste is so unpalatable that the predator learns to never eat them again. Also the adults use their control of their light to attract other genders. How sexy right? Lol Imagine if we had lights on our butts that attracted our significant others!!!! LOLOL
Who would’ve thought that all this happens in those little bodies? I also just want to point out that when you do capture them in jars make sure you put holes in the lid to allow the oxygen to come in and out so they can glow!!!
Now go collect those bugs!!
Xoxo, Z
