What is the nitrogen cycle?
Q: What is the nitrogen cycle?
A: The nitrogen cycle is the process by which nitrogen in nature is changed into different forms that can be used by living organisms.
Q: How much of air is made up of nitrogen?
A: Air is composed of approximately 78% nitrogen.
Q: What role does nitrogen play in living things?
A: Nitrogen plays an important role in proteins, DNA, and RNA, as well as photosynthesis and growth in plants.
Q: How does elemental nitrogen become usable for life?
A: Elemental nitrogen must undergo a process called nitrogen fixation to be converted into forms that are usable for life. This process typically involves bacteria with an enzyme that combines N2 with hydrogen gas (H2) to make ammonia (NH3).
Q: How do plants obtain their necessary supply of nitrogen?
A: Plants obtain their necessary supply of nitrogen from either bacteria living in their roots or from compounds taken out of the soil through their roots. All animals obtain their supply of nitrogren from eating plants.
Q: What processes take place when ammonium levels are too high?
A: When ammonium levels are too high, a process called nitrification must occur which involves the oxidation of ammonia and ammonium to nitrite (NO2−) and then to nitrate ( NO3−) by bacteria. High nitrate levels can cause blue-baby syndrome if present in drinking water and too much algae growth if present in lakes or pools.
Q: How does denitrification start the cycle over again?
A Denitrification occurs when some bacteria convert nitrate into nitrogen gas (N2), releasing energy during this process, thus starting the cycle over again.
