The Nitrogen Cycle
Studied by 0 people
Learn
Practice Test
Spaced Repetition
Match
Flashcards1/42
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
|---|
No study sessions yet.
43 Terms
What percent of the air is nitrogen?
78 percent
78 percent of what is nitrogen?
the air
Why is nitrogen essential to life?
because it is a key component of amino acids, nucleic acids, and ATP
What is a key component of amino acids, nucleic acids, and ATP?
nitrogen
Do plants and animals obtain nitrogen directly from the atmosphere?
no
From what do plants and animals obtain nitrogen?
nitrogen fixation
What key players in nitrogen fixation?
legumes and symbiotic bacteria that are associated with their root nodules
Legumes and symbiotic bacteria that are associated with their root nodules are key players in what?
nitrogen fixation
What do legumes include?
clover, peas, alfalfa, and soybeans
What includes clover, peas, alfalfa, and soybeans?
legumes
What are the bacteria associated with their root nodules?
nitrogen fixing bacteria
What are nitrogen fixing bacteria?
bacteria associated with their root nodules
What do nitrogen fixing bacteria do?
convert nitrogen in the soil to ammonia (NH3), which can be taken up by some plants
What converts nitrogen in the soil to ammonia (NH3), which can be taken up by some plants?
nitrogen fixing bacteria
The nitrogen fixing bacteria and legumes are in what?
a symbiotic relationship
What are in a symbiotic relationship?
nitrogen fixing bacteria
What are nitrogen fixing bacteria in aquatic ecosystems?
cyanobacteria
What are cyanobacteria?
nitrogen fixing bacteria in aquatic ecosystems
How is nitrogen fixed into the soil?
through the action of free-living bacteria and through nitrogen fixing bacteria
What happens through the action of free-living bacteria and through nitrogen fixing bacteria?
nitrogen fixation
What is the soil a major reservoir for?
ammonia and other nitrogen-containing compounds
What is a major reservoir for ammonia and other nitrogen-containing compounds?
the soil
What is nitrogen fixation?
the process that converts atmospheric nitrogen into ammonia
What is the process that converts atmospheric nitrogen into ammonia?
nitrogen fixation
What is ammonification?
the process that converts organic nitrogen from dead matter and waste into ammonia by fungi and bacteria
What is the process that converts organic nitrogen from dead matter and waste into ammonia by fungi and bacteria?
ammonification
What is the first step of nitrification?
nitrosomonas convert ammonia to nitrite (NO2)
When does nitrosomonas convert ammonia to nitrite (NO2)?
the first step of nitrification
What is the second step of nitrification?
Nitrobacter converts nitrite into nitrate (NO3)
When does nitrobacter converts nitrite into nitrate (NO3)
the second step of nitrification
What happens after nitrification?
some plants consume nitrate, and they are then consumed by consumers
When do some plants consume nitrate, who are then consumed by consumers?
after nitrification
What is denitrification?
nitrates in the soil are broken down by organisms and nitrogen to be released as atmospheric nitrogen
What is the process of nitrates in the soil are broken down by organisms to be released as atmospheric nitrogen?
denitrification
What is denitrification performed by?
a variety of microscopic bacteria, fungi, and other organisms
What are performed by a variety of microscopic bacteria, fungi, and other organisms?
denitrification
What are the steps of the nitrogen cycle?
nitrogen fixation, ammonification, nitrification, denitrification
How is lightning involved in the nitrogen cycle?
Lightning’s energy breaks down atmospheric nitrogen into nitrogen oxides which are watered down to nitrate in the soil
Why do herbivores need nitrogen?
for the synthesis of key organic compounds like amino acids, proteins, and nucleic acids
What are the three processes that fix nitrogen?
nitrogen fixation, industrial fixation (Haber), and atmospheric fixation (lightning)
nitrogen fixation, industrial fixation (Haber), and atmospheric fixation (lightning) are what processes?
the three processes that fix nitrogen
What are the major reservoirs for nitrogen?
the soil and the atmosphere
Why may farmers plough a crop of legumes into the ground rather than harvest it?
legumes make nitrogen available for plants, reducing the need for fertilizers