Welcome to brain Stuff, a production of I Heart Radio. Hey, brain Stuff, Lauren Vogel bomb 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 seventy percent 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 bucket full of Icelandic money and say Minneapolis, where you can't spend it. And we spoke by email with Jesse Moates, a PhD candidate at the Odum 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 called 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. And this is the cycle of a nitrogen atom on Earth, and its journey starts either very quietly or with a humongous bang.
The step one in the cycle is nitrogen fixation. Believe it or not, Lightning and bacteria are the two things primarily responsible for turning atmospheric nitrogen into nitrogen that living things can use. Atmosphere nitrogen is very stable, so it takes an incredible amount of energy to convert it to a different form. If you've ever wondered why your outdoor plants seem happier after a thunderstorm than they do when you turn a sprinkler on them, there's a reason for that.
Lightning electrifies atmospheric nitrogen and water to reconfigure them into ammonia and nitrates. This falls to the ground is rain, where plants slurp it up and use it for their biological processes. On the other end of the spectrum, the most common way nitrogen is made available to organisms is when atmospheric nitrogen is fixed by bacteria, and some of which live free in the soil, and others of which
enjoy a symbiotic relationship with certain plant species. Lagoons like peas, clover, and peanuts have little nodules on their roots that attract bacteria that convert stubborn atmospheric nitrogen into ammonia or ammonium, which can then be used to power the plant. Step too,
is nitrification. Ammonia in the soil can be used directly by plants, but it's all so a step in the process of nitrification, through which specialized bacteria and other microorganisms convert ammonia into nitrite and then pass it off to an entirely different set of micro organisms that further oxidize the nitrate into nitrate. This process is slow, but it's the way that nitrogen is built as a nutrient. In soil and aquatic and marine environments. Terrestrial plants, for instance,
can absorb ammonium and nitrate through their root hairs. The organisms that specialize in nitrification are also important in treating municipal wastewater, and anyone who's kept an aquarium knows how important those organisms are to keeping your water, fish and plant friendly. Step three is a monification. Everything living eventually dies and the nitrogen a particular organism was using when
it shuffled off. This mortal coil is taken to hand by bacteria that turned the nitrogen rich corpse into ammonium, which can be picked back up by plants and used again. The step four is D nitrification. It's possible to convert bioavailable nitrogen into atmospheric nitrogen again, and that process is called unitrification. Nitrification is performed by bacteria and other microorganisms
that can tolerate oxygen. Not all microorganisms can. In the case of D nitrification, certain anaerobic bacteria that don't need oxygen convert nitrate to nitrogen gas, which floats up into the atmosphere and plays hard to get again until some lightning or crafty bacterium comes along and ropes it. Back into the first step of the nitrogen cycle yet again. Today's episode was written by Justesceline Shields and produced by Tyler Klang. For more on this and lots of other
cyclical topics, visit how stuff works dot com. Brain Stuff is production of by Heart Radio. Or more podcasts to my heart radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.