3. Nutrient Cycle In Natural Ecosystems Flashcards
What is a natural ecosystem defined as being?
One that hasn’t been changed by humans.
Nitrogen/ phosphorous recycled through food webs.
What 2 things do saprobiants do ?
They feed on remains of dead plants / animals/ waste products, breaking them done.
Secrete enzymes and digest food externally, then absorb nutrient they need.
Because saprobiants break down deal animals and plants, what can they be considered to be ?
Decomposers.
Allows important chemical elements to be recycled
What is it called when saprobiants digest food externally?
Extracellular digestion.
What happens during extracellular digestion?
Organic molecules broken down into inorganic ions.
What is it called when you obtain nutrients from dead organic matter and animal waste using extracellular digestion?
Saprobiotic nutrition
Define mycorrhizae
A symbiotic relationship between a fungus and roots of the plant.
Fungi structure
Long thin strands called hyphae
These connect to plant roots
Function of hyphae
Greatly increase surface area of plants root helping to absorb ions from soil
Greatly increase water uptake.
Name an ion in the soil.
Phosphorus
What to fungi overall obtain?
Organic compound like glucose from plant.
What is a symbiotic relationship ?
When 2 species live closely together and one or both species depends on one another do survival.
Why do plants and animals need nitrogen?
Proteins and nucleic acids
Dna and rna
What % of atmosphere is nitrogen?
78%
Why is nitrogen in atmosphere not great?
Plants and animals can’t use it in this form.
So they need bacteria to convert it into nitrogen containing compounds.
Bacteria’s role in nitrogen cycle.
Converts atmospheric nitrogen into nitrogen containing compounds.
What does nitrogen cycle show ?
How nitrogen is converted into usable forms and then passes on between different organisms and Non living environment.
Includes food chains ( as nitrogen passed on when organisms are eaten)
4 different processes
Name the 4 different processes in nitrogen cycle.
Nitrogen fixation
Ammonification.
Nitrification
Dentrification
N - AND
What happens in nitrogen fixation ?
Nitrogen gas in atmosphere is turned into nitrogen containing compounds.
What is biological nitrogen fixation carried out by ?
Bacteria
Which turns nitrogen into ammonia, this forms ammonium ions in solution that can be used by plants
Where are the bacteria’s found?
Root nodules.
Leguminous plants.
Soul
What type of relationship do the bacteria and plant form ?
Mutualistic relationship - they provide plants with nitrogen containing ions and plant provides them with carbohydrates.
What happens in ammonification ?
Nitrogen compounds from dead organisms are turned into ammonia saprobiants, which go on to form ammonium ions.
What does animal waste contain and what does this get turned into ?
Nitrogen compounds which turned into ammonia by saprobiants , go on to form ammonium ions.
(Ammonification)
What happens in nitrification?
Ammonia ions in soil are changed into nitrogen compounds which can be used by plants - nitrates.
What does nitrifying bacteria do ?
Changes ammonium ions unto nitrites.
Nitrification
What bacteria becomes nitrified?
Nitrosomonas
Nitrification
What does nitrifying bacterial called nitrobacter do ?
Nitrites to nitrates.
Nitrifying nitrosomonas?
Ammonium ions into nitrites
What happens in dentrification?
Nitrates in soil converted into nitrogen gas by dentrifying bacteria - use nitrates in soil to carry out respiration and produce nitrogen gas.
Happens under anaerobic conditions.
Where does dentrification occur?
Where there’s no o2 anaerobic conditions
Water logged soil
Name 2 other ways nitrogen into an ecosystem?
Lightening.
Artificial fertilisers.
Lightening.
Fixes atmospheric nitrogen into nitrogen oxides.
Artificial fertilisers.
Produced from atmospheric nitrogen on industrial scale in Haber process
