Question

Nitrogen cycle causes and conqunces of exceeding loading

Answer 1

What are the consequences of disrupting the nitrogen cycle?

Scientists have determined that humans are disrupting the nitrogen cycle by altering the amount of nitrogen that is stored in the biosphere. The chief culprit is fossil fuel combustion, which releases nitric oxides into the air that combine with other elements to form smog and acid rain.

Answer 2

Nitrogen is everywhere! In fact, \text N_2N2​N, start subscript, 2, end subscriptgas makes up about 78% of Earth's atmosphere by volume, far surpassing the \text O_2O2​O, start subscript, 2, end subscript we often think of as "air".^11start superscript, 1, end superscript

But having nitrogen around and being able to make use of it are two different things. Your body, and the bodies of other plants and animals, have no good way to convert \text N_2N2​N, start subscript, 2, end subscript into a usable form. We animals—and our plant compatriots—just don't have the right enzymes to capture, or fix, atmospheric nitrogen.

Still, your \text{DNA}DNAD, N, A and proteins contain quite a bit of nitrogen. Where does that nitrogen come from? In the natural world, it comes from bacteria

bacteria plays a key role in nitrogen cycle

Nitrogen enters the living world by way of bacteria and other single-celled prokaryotes, which convert atmospheric nitrogen—\text N_2N2​N, start subscript, 2, end subscript—into biologically usable forms in a process called nitrogen fixation. Some species of nitrogen-fixing bacteria are free-living in soil or water, while others are beneficial symbionts that live inside of plants.