Welcome to BrainStuff, a production of I Heart Radio.

Hey Brain Stuff, Lauren Vogelbaum here.

Everybody needs nitrogen, but as far as non-negotiable life-sustaining elements go, it's tricky. Living things require nitrogen for their cells to function, and furthermore, we're virtually steeping in the stuff since our

atmosphere is made up of 78% nitrogen gas. However, there's a catch. It's a water, water

everywhere, but not a drop to drink kind of situation.

Although nitrogen is floating basically everywhere,

it's not terribly abundant in the Earth's crust.

And it's incredibly difficult for living things to capture atmospheric nitrogen and use it for their purposes.

It's like having a bucketful of Icelandic money in, say, Minneapolis, where you can't spend it.

And we spoke by email with Jesse Motes, a

PhD candidate at the Odom School of Ecology at the University of Georgia. She

said, nitrogen is a major part of amino acids which are the building blocks of proteins

and nucleic acids such as DNA. In addition to needing nitrogen for proteins and

plants it's a main component of chlorophyll, which makes it crucial for photosynthesis.

Since nitrogen is a limited resource on this planet,

a nitrogen atom doesn't spend much time doing nothing

when it's in a form that living things can use.

Scientists call nitrogen in this form, fixed.

A fixed nitrogen is taken up by plants, which are eaten by animals,

which eat other animals, which die and decompose, and release nitrogen back into the ecosystem to be worked on by bacteria or plants. This is the cycle of a nitrogen atom on Earth, and its journey starts either very quietly or with a humongous bang.

Step one in the cycle is nitrogen fixation.

Believe it or not, lightning and bacteria are the two things primarily responsible for turning atmospheric

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