Translations:AY Honors/Ecology - Advanced/Answer Key/28/en

After being used by plants and animals, nitrogen is then disposed of in decay and wastes. Detritivores and decomposers decompose the detritus from plants and animals, nitrogen is changed into ammonia, or nitrogen with 3 hydrogen atoms (NH₃). Ammonia is toxic and cannot be used by plants or animals, but nitrite bacteria present in the soil can take ammonia and turn it into nitrite, nitrogen with two oxygen atoms (NO₂). Although nitrite is also unusable by most plants and animals, nitrate bacteria changes nitrites back into nitrates, usable by plants and animals. Some nitrates are also converted back into nitrogen gas through the process of denitrification, which is the opposite of nitrogen-fixing, also called nitrification. Certain denitrifying bacteria are NOT responsible for this.