Nutrient cycles Flashcards
Nutrient
A substance used by an organism to survive, grow and reproduce
Saprobionts
Decomposers like bacteria and fungi which break down dead material and absorb to use the nutrients
Saprobiotic nutrition
When a saprobiont secretes enzymes out of cell that will digest the dead material and absorb the nutrients produced
In external, digestion
Left over nutrients from saprobiotic nutrition is…
Left behind in soil for other organisms
Nitrogen cycle
How nitrogen moves and is recycled in ecosystems
Dead material containing nitrogen eg DNA and protein is…
Decomposed by saprobionic nutrition and released as ammonium ions
Ammonification
Decomposition of dead material by saprobionts releases ammonium
Ammonium is converted to what..?
Nitrite then nitrate
Nitrification
Oxidation of ammonium to nitrite then nitrate ions by nitrifying bacteria
What completes nitrification of ammonium?
Nitrifying bacteria
What converts nitrate back to N2 gas for the atmosphere?
Denitrifying bacteria
Reduction of nitrates to nitrogen process is called…
Denitrification
Nitrates in soil use
Enter plant roots via active transport to form proteins/DNA
Process which converts nitrogen gas in atmosphere back to ammonium ions?
Process called nitrogen fixing
What converts nitrogen gas to ammonium ions in nitrogen fixing?
Nitrogen fixing bacteria
Where does nitrogen fixing bacteria live?
In root nodules of legume plants
Denitrifying bacteria lives best in…
Anaerobic soils
What causes anaerobic soils?
Water logging which reduces air packets in soil
What bacteria works best under aerobic conditions?
Nitrifying bacteria
Nitrogen fixing bacteria
What causes aerobic soil?
Ploughing
Phosphate ions usage
In ATP/ADP
in RNA/DNA
How does the phosphate cycle start?
Saprobionts externally digest dead material eg dna from animals/plants which releases phosphate into the soil
Where does the phosphate released into soil to?
Leeched into water bodies
Absorbed back into plants
Phosphate leeched into water…
In solution and then Enters aquatic foodwebs
The dead material sinks to form sediments at the bottom
Sediments containing phosphate ions will rise to the surface..
Then weather down to release phosphate back to soil
Phosphate ions in solution in soil will..
Enter plant roots via active transport
Used for dna etc then enters foodwebs by being eaten by animals which eventually die and cycle continues
What is a Mycorrhizae?
An association between a fungus and a plant root
How does the fungus in a mycorrhizae help?
Acts as an extension of the root so increases surface area of root so can absorb more nutrients AND WATER (nitrate and phosphate ions) from soil to give to the plant for more growth: making proteins
And DNA/ATP/RNA
How does the plant of the root in a mycorrhizae help the fungus?
Shares its organic substances from photosynthesis eg glucose with it so can aerobically respire more
