Nutrient Cycles Flashcards
How do free-living bacteria undergo nitrogen fixation?
- reduce nitrogen to ammonia
- to make amino acids
- when they die they release nitrogen rich compounds
How do mutualistic bacteria undergo nitrogen fixation?
- reduce nitrogen to ammonia
- In nodules of legumous plants
- get carbohydrates from the plant
- give amino acids to the plant
What is the process of ammonification?
- decomposers feed on dead material
- they release ammonia
- Ammonia makes ammonium ions in the soil
- Nitrogen is returned to the soil
What is the process of nitrification?
- nitrifying bacteria convert ammonium ions to nitrite ions by oxidation
- then convert nitrite ions to nitrate ions by oxidation
What is dentrification?
In anaerobic conditions
-dentrifying bacteria convert nitrates to nitrogen gas
Explain the nitrogen cycle
-Atmospheric nitrogen is converted to nitrogen compounds in plants via nitrogen fixing
-nitrogen compounds in plants is either:
-consumed by animals
- converted to ammonium compounds via ammonification
– nitrogen in animals is converted to ammonium compounds via
Ammonification
- ammonium is converted to nitrites then to nitrates by nitrification
-The nitrates are absorbed by plants in aerobic conditions
- the nitrates are converted to nitrogen gas by dentrification in anaerobic conditions
Explain the process of the carbon cycle?
- carbon From water and air is passed to the plants via photosynthesis
- primary consumers eat plants therefore carbon is passed to them
- when consumers die, decomposers digest them and so get carbon compounds
- if detritus is not digested, they’re turned to fossil fuels
- when fossil fuels are burnt, they release carbon into the air ( combustion)
What are the consequences of increased carbon gases in the atmosphere?
- melt polar ice caps : extinction of organisms
- rise in sea levels: thermal expansion of oceans, reduce biodiversity, salt effect crops
- increased temperature and decrease rainfall: failed crops, xerophytes would grow, alter distribution of organisms
- increased rainfall and intensify storms: alter distribution of organisms
- life cycles of insects and pests would be altered: disease could spread
Possible benefits of increased carbon gases in the atmosphere?
- fill reservoirs
- grow crops in places where couldn’t before
- increase photosynthesis: harvest twice a year possibly
What is nitrogen fixation?
Turning nitrogen gas to nitrogen containing compounds