Nitrogen Cycle Flashcards
What process converts N2 into NH4+?
nitrogen fixation
What are 2 examples of anaerobic conditions?
- very compact soil
- water-logged soil
Draw the nitrogen cycle
use book
How are plants involved in the nitrogen cycle?
they assimilate NO3 (using it in proteins, DNA, RNA etc.)
their nitrogen containing compounds are broken down by saprobionts
How can lightning be involved in the nitrogen cycle?
it can break the bond between N2, allowing nitrogen to react with oxygen and form nitrates, without the need for bacteria
How are nitrate ions taken up by roots?
active transport
What are the 4 main stages in the nitrogen cycle?
- nitrogen fixation
- nitrification
- ammonification
- denitrification
What is ammonification?
production of ammonia from nitrogen containing compounds (eg urea, proteins and nucleic acids) found in waste and dead organisms
What do ammonifying bacteria do?
convert nitrites into ammonia
What microorganisms carry out ammonification?
saprobionts
What is nitrification?
the oxidation reaction converting ammonium ions into nitrate ions
What microorganisms carry out nitrification?
nitrifying bacteria
What is required for nitrifying bacteria to carry out nitrification?
oxygen (aerated soil)
What is nitrogen fixation?
the process converting atmospheric nitrogen into ammonia and ammonium ions
What are the types of nitrogen fixing bacteria?
free-living and mutualistic