N cycle

Question 1

atmospheric nitrogen -> ammonia

Answer 1

nitrogen fixation
- carried out by N fixing bacteria that turns N into ammonia
- ammonia goes on to form ammonium ions in solution that can be used by plants
- rhizobium found in root nodules

Question 2

ammonium ions -> nitrites -> nitrates

Answer 2

nitrification
- ammonium ions in soil are changed into nitrates that can be used by plants
- nitrifying bacteria called nitrosomomas change ammonium ions into nitrites
- nitrobacter change nitrites into nitrates

Question 3

nitrates -> nitrogen compounds in plants

Answer 3

-> nitrogen compounds in animals
- animals consume plants

Question 4

nitrogen compounds in animals and plants -> ammonia

Answer 4

ammonification
- N compounds from dead organisms are turned into ammonia by saprophytes
- ammonia goes on to form ammonium ions
- animal waste is also turned into ammonia

Question 5

nitrates -> atmospheric nitrogen

Answer 5

denitrification
- nitrates in soil are converted into N gas by denitrifying bacteria
- use nitrates in soil to respire and produce N gas under anerobic conditions